wi-fi phone usability and utility - kth

Wi-Fi Phone Usability and Utility

A usability evaluation of Hitachi WirelessIP5000, Ascom i75 and Accton VM1188T connected to Ericssons’s PBX MX-ONE™

L I N D A E R I K S S O N

Master of Science Thesis Stockholm, Sweden 2006

Wi-Fi Phone Usability and Utility

A usability evaluation of Hitachi WirelessIP5000, Ascom i75 and Accton VM1188T connected to Ericssons’s PBX MX-ONE™

L I N D A E R I K S S O N

Master’s Thesis in Human Computer Interaction (20 credits) at the School of Media Technology Royal Institute of Technology year 2006 Supervisor at CSC was Kerstin Severinson Eklundh Examiner was Kerstin Severinson Eklundh TRITA-CSC-E 2006:159 ISRN-KTH/CSC/E--06/159--SE ISSN-1653-5715 Royal Institute of Technology School of Computer Science and Communication KTH CSC SE-100 44 Stockholm, Sweden URL: www.csc.kth.se

Abstract Wi‐Fi Phone Usability and Utility

Wi-Fi phones, wireless IP phones, is an interesting telephony solution for many enterprises since the same network can be used for data as well as voice communication, saving costs and offering new possibilities. These Wi-Fi phones, which look like any other wireless or mobile phone, wirelessly connect to the company’s PBX making it possible to use many telephony functions, such as call-back, telephone conference etc. This Master’s thesis, performed at Ericsson Enterprise describes usability tests and evaluations establishing how user friendly it is to use telephony functions in the PBX MX-ONE™ using the Wi-Fi phone Hitachi WirelessIP5000. A comparative usability evaluation is also carried out on the Wi-Fi phones Ascom i75 and Accton VM1188T. The Master’s project also involved identifying the predicted Wi-Fi phone users. The goal was to come up with proposals of how the usability can be increased in using a Wi-Fi phone connected to MX-ONE. The outcome was that the probable Wi-Fi phone users are people who have high on-premises mobility, such as Blue-collar workers, nurses, IT staff and managers. Ascom i75 is the most suitable Wi-Fi phone for this target group. The usability tests and evaluations revealed a lack of status awareness and feedback from the PBX. Furthermore there were several buttons on the Wi-Fi phones that several test participants had problems with. There was also a lack of confirmation from the PBX. It was also apparent that the test participants did not know where do find guidance and also found the PBX codes confusing and difficult. The usability can be increased by activating the PBX functions via the phones’ menus or by a voice activated service. The users should also receive more guidance from quick guides and online guidance where FAQ:s and manuals can be found. Furthermore, the users should get more feedback using audio or text messages.

Sammanfattning Användbarhet och funktionalitet i Wi‐Fi‐telefoner

Trådlösa IP-telefoner, så kallade Wi-Fi-telefoner, är ett intressant telefonialternativ för många företag. Dels för att samma nätverk kan användas för telefoni och datakommunikation, vilket drar ner kommunikationskostnaderna, och dels för att Wi-Fi-telefoni öppnar upp för nya möjligheter i framtiden, då olika teknologier och funktioner kan integreras i samma apparat. De flesta Wi-Fi-telefoner liknar till utseendet en mobiltelefon eller trådlös telefon och kan trådlöst ansluta sig till en företagsväxel och nyttja dess telefonitjänster såsom vidarekoppling och telefonkonferens. Detta examensarbete utfördes på Ericsson Enterprise och fastställer hur användarvänligt det är att nyttja telefoni-funktioner i Ericssons växel MX-ONE via Wi-Fi-telefonen Hitachi WirelessIP5000. En jämförande användbarhets-utvärdering utfördes på två andra Wi-Fi-telefoner; Ascom i75 och Accton VM1188. Arbetet bestod även i att identifiera de förmodade Wi-Fi-telefonianvändarna. Målsättningen var att presentera förslag på hur användbarheten kan ökas. De troliga användarna av Wi-Fi-telefoner visade sig vara personer med hög mobilitet inom företagets lokaler, såsom industriarbetare, sjuksköterskor, IT-personal och chefer. Ascom’s Wi-Fi-telefon i75 är mest anpassad och lämplig för denna målgrupp. Användartesterna och utvärderingarna åskådliggjorde ett antal problem. Bland annat var det en uppenbar brist på åter-koppling och bekräftelser. Flera knappar på telefonerna orsakade också problem då de ej var märkta tillräckligt bra. Det blev också tydligt att testpersonerna inte visste var de kunde hitta hjälp och att de hade problem med koderna som används för att aktivera växeltjänster. Användbarheten ökar betydligt om växelfunktionerna kan aktiveras i telefonen eller via en röststyrd tjänst. Genom att ge användarna mer manualer och annan ledning, delvis online, kan användarvänligheten ökas ytterligare. Användarna borde även få mer textbaserad och audiell återkoppling.

Acronyms & Glossary This page provides definitions for the acronyms, abbreviations and central terms used in this report.

Access point - A device that wireless communication gadgets connect to in order to access a network. In this report Access point refers to a router or switch using the internet protocols IEEE 802.11b/g.

DECT – Digital Enhanced Cordless Tele-communications. A standard for wireless phones.

DECT phone – A wireless phone based on the DECT standard. DECT phones are common in corporate and domestic environments.

Extension - A telephone attached to a PBX.

H.323 – A telephony standard from ITU with protocols for voice communication on a packet network.

HCI – Human computer interaction. The study of the interaction between people and machines or systems, with a focus on usability.

Heuristic evaluation – a usability evaluation technique where a system or product is evaluated based on usability goals, formed by the HCI expert Jacob Nielsen. See section 4.1.3.

IP - Internet Protocol. A global protocol for transfer-ring data between devices over a data network, often using the Internet.

IP telephony - Telephony over an IP based network, such as the internet. Also called VoIP (Voice over IP) or Internet Telephony.

KTH – Kungl. Tekniska Högskolan. Royal Institute of Technology in Stockholm.

LAN – Local Area Network. A computer network covering a certain area. Most LANs are IP networks, and are common in homes and offices.

MX-ONE™ 3 – A telephony system developed by Ericsson Enterprise. Version 3 enables Wi-Fi telephony.

PBX -Private Branch Exchange. The central unit in a telephony system often owned by an enterprise. The PBX switches internal and external calls within the enterprise.

PBX code – A combination of numbers dialed on a phone to activate PBX functions. For instance, 5 is dialed to activate call-back.

PBX function – Telephony functionality found in the PBX, and not in the phone. Examples of PBX functions is telephone conferencing, transferring calls, call-back and absence notice.

QoS – Quality of Service. The quality of the phone call, such as lack of noise, appropriate sound level, no delays etc.

SIP – Session Initiation Protocol. A protocol for sessions, such as phone calls, between two or more people. The protocol was formed by IETF and is commonly used for Wi-Fi telephony.

WAP – Wireless Application Protocol, a global standard for the communication between wireless gadgets for instance for getting internet access in a mobile phone.

Wi-Fi - Wireless Fidelity. Wireless IP

Wi-Fi telephony - Telephony over a wireless IP based network. Also called VoWLAN (Voice over WLAN).

Wi-Fi phone – A wireless phone operating on a Wi-Fi network.

WLAN – Wireless Local Area Network. A local network of computers and other devices that are connected wirelessly to access point(s), often using the Wi-Fi standard.

VoIP- See IP telephony.

VoWLAN – See Wi-Fi telephony.

Preface This is a Master’s thesis report in Human Computer Interaction at the Royal Institute of Technology (KTH) in Stockholm at the School of Computer Science and Communication. At KTH I have attended the Media Technology Master of Science in Engineering program. This Master’s project has been conducted at Ericsson Enterprise in Stockholm. I would like to use this preface as an opportunity to thank all the people who contributed to the realization of this project. First of all I would like to thank my tutor at Ericsson Enterprise, Fredrik Kjebon, for all his help and support during the entire process. He has at all times assisted me and guided me through the telecom wilderness. I would also like to thank my tutor at KTH, Prof. Kerstin Severinson Eklundh, for her good advice and help with the report. Moreover, I have been in contact with many people at Ericsson Enterprise, within Sales and Marketing as well as Development, who have offered their time helping me and contributed by participating in interviews. Some of these, to whom I want to express my gratitude, are Mats Höglander, Marcus Junthé, Lars Berggren, Anders Holm, Lars Hindersson and Per Åström. I would also like to thank all the people who participated in the usability tests as well as my family and friends. Linda Eriksson Stockholm, November 2006

Table of Contents 1. Introduction............................................................................................................................................... 1

1.1 Background ........................................................................................................................................................... 1 1.2 Problem Definition, Purpose & Aim..................................................................................................................... 1 1.3 Limitations ............................................................................................................................................................ 2 1.4 Report Disposition ................................................................................................................................................ 2

2. Method ....................................................................................................................................................... 3 2.1 Literature Study..................................................................................................................................................... 3 2.2 Categorizing Users & Customers ......................................................................................................................... 3 2.3 Composition of Test Sessions ............................................................................................................................... 3 2.4 Conducting the Tests on Hitachi WirelessIP5000................................................................................................. 5 2.5 Comparison with Ascom i75 & Accton VM1188T.............................................................................................. 6 2.6 Analysis & Report Writing ................................................................................................................................... 6

3. Technical Aspects...................................................................................................................................... 7 3.1 Telephony.............................................................................................................................................................. 7 3.2 Technological Baseline ......................................................................................................................................... 9

4. Theory ...................................................................................................................................................... 12 4.1 Usability & Human Computer Interaction Theory.............................................................................................. 12 4.2 Study of Similar Research................................................................................................................................... 14

5. Customer & User Groups ...................................................................................................................... 17 5.1 Wi-Fi Telephony System Customer Groups ....................................................................................................... 17 5.2 Wi-Fi Phone User Groups ................................................................................................................................... 19

6. Hitachi WirelessIP5000 Usability Test Findings................................................................................. 23 6.1 Findings Regarding Hitachi WirelessIP5000 ...................................................................................................... 23 6.2 Findings Regarding the Web Interface............................................................................................................... 25 6.3 System Related Findings..................................................................................................................................... 25 6.4 Rated Findings Summary .................................................................................................................................... 26 6.5 Mental Model ...................................................................................................................................................... 27

7. Comparison with Ascom i75 & Accton VM1188T.............................................................................. 29 7.1 Comparative Usability Evaluation ..................................................................................................................... 29 7.2 Summarizing Table ............................................................................................................................................. 34

8. Results Analysis & Proposals................................................................................................................. 35 8.1 Results Analysis .................................................................................................................................................. 35 8.2 Conclusions from the Phone Comparison ........................................................................................................... 36 8.3 Functionality of Interest for the Users................................................................................................................. 36 8.4 Phone Specific Proposals .................................................................................................................................... 37 8.5 PBX Related Proposals ....................................................................................................................................... 38

9. Discussion ................................................................................................................................................ 42 9.1 Usability in Complex Technical Systems............................................................................................................ 42 9.2 Results Discussion .............................................................................................................................................. 42 9.3 Method Discussion.............................................................................................................................................. 43

9.4 Validity & Reliability.......................................................................................................................................... 43 9.5 Recommendations for Further Studies ................................................................................................................ 43

References ...................................................................................................................................................... 45 Appendices ..................................................................................................................................................... 48

Appendix A: Test Plan .............................................................................................................................................. 49 Appendix B: Screening Questionnaire ...................................................................................................................... 53 Appendix C: Post-task Questionnaire ....................................................................................................................... 54 Appendix D: Post-test Session Questionnaire........................................................................................................... 55

CHAPTER 1. INTRODUCTION 1

1. Introduction In this chapter a background to telephony and IP communication is given as well as the problem definition and limitations for this Master’s project. At the end of the chapter there is a disposition section that explains the outline of this report.

1.1 Background Although telephony has existed for quite a long time now, it is an advancing field. Manual switchboards have been replaced by electromechanical switches. To-day, electronic digital switches are the most common type, enabling features that no-one would have consid-ered possible a few decades ago. Telephony is so much more than switchboards, copper wire and speech. Now-adays it can be either wireless or wired communication involving many different services and media types. Whilst telephony is advancing; telephone networks and data networks are converging. The borderline between these systems is slowly dissolving as the Internet is used for making and routing calls and the telephone network has been used for Internet access for years. The Internet Protocol (IP) plays a major role in this convergence. Many predict that IP soon will be used for all type of communication systems (Person 2005; Vitella 2005). This is largely based on the increased demand and possibilities of IP solutions. IP telephony, for instance, has increased during the last couple of years among enterprises as well as home users. These possibilities have partly to do with the technological advancement enabling addressing and higher sound quality and partly because IP telephony offers enter-prises a communication convergence where the same network can be used for both voice and data com-munication thereby cutting expenses. Not only is IP telephony cost efficient, it also enables new features and functionality, such as integrating text, video and voice communication. Simultaneously, many new wireless IP networks (WLANs) are built opening up for wireless IP telephony (Wi-Fi telephony). This enables more mobility as well as the increased communication possibilities that IP telephony offers, making Wi-Fi telephony an interesting alternative for many enterprises.

Ericsson Enterprise has developed a telephony system called MX-ONE™ version 3 that enables wireless IP telephony. It is therefore possible to connect to a MX-ONE Telephony System using wireless IP phones, called Wi-Fi phones. It is, however, uncertain how Wi-Fi phones will be received by the end users and how it is for them to use the applications and functions the MX-ONE system offers via these. Usability is an important issue when introducing new technologies. During the Wi-Fi Busi-ness Development Summit about Convergence in 2005, at least five of the 30 speakers mentioned the import-ance of easy-to-use products, which confirms the sub-ject’s importance. Furthermore, Disruptive Analysis predicts that there will be 46.0 million Wi-Fi phones on the market by 2009 (Bubley 2005).

1.2 Problem Definition, Purpose & Aim This Master’s project, at Ericsson Enterprise, aims to determine who the probable users of Wi-Fi phones are and how high the usability is for them to use a Wi-Fi phone connected to a MX-ONE Telephony System and use its features. Examples of such features are parking a call, voice mail and activating call-back. The following Wi-Fi phones have been evaluated:

(i) Hitachi WirelessIP5000 (ii) Ascom i75 (iii) Accton VM1188T.

I have however mainly focused on the Wi-Fi phone Hitachi WirelessIP5000. The other phones were added at a later stage and have therefore not been part of the usability evaluation. The project has resulted in a description of what works well for the users and what is in need of improvement

CHAPTER 1. INTRODUCTION 2

as well as in proposals of how the usability can be increased. Partly, this Master’s project has to do with the usability challenges that may occur as a result of the technical advancement resulting in smaller and more complex products and applications. What was previously per-formed on big, stationary telephones with many lights, diodes and buttons, including preprogrammed func-tional buttons, is now to be performed on small Wi-Fi phones with fewer buttons and a smaller display. Another aspect of this project is the possible com-plications due to several technical systems and compo-nents being joined together. Difficulties that a user has with his or her phone can actually have to do with the network or the PBX. It is uncertain if the users can make this separation between the different components and if this generates a greater understanding of how Wi-Fi phones work.

1.3 Limitations This Master’s project is limited to Wi-Fi telephony in a single cell. As a result, problems that have to do with multi cell use, such as roaming and hand over are not covered. Obvious errors, such as system failures, are also excluded from the project. This project is also limited to the regular end users and will not cover the telephone administrators and other personnel responsible for installing and configuring the MX-ONE system and Wi-Fi phones. I had to limit the number of participants in the usability tests of Hitachi WirelessIP5000, and could therefore not test people from all target groups and sectors. As mentioned, Ascom i75 and Accton VM1188T were in-cluded into the Master’s project at a rather late stage, when the usability tests had already been conducted. There was therefore not enough time for performing usability tests on these phones.

1.4 Report Disposition This report is divided into nine chapters. These chap-ters are organized as follows. This first chapter presents the background and purpose of this project including the scope of the report. Chapter two presents the used methods and involves a description of how the usability tests were prepared and conducted as well as information about the liter-ature study.

The following chapter, chapter three, gives an introduction to telecom and IP telephony and also presents the technology baseline for this Master’s project. This involves the PBX and the Wi-Fi phones that were evaluated. This foundation of knowledge is essential in order to understand the rest of the report. Readers that are already familiar with Wi-Fi telephony, MX-ONE and the three evaluated Wi-Fi phones may skip this chapter. The fourth chapter presents usability theory and usa-bility testing; the theoretical foundation for this project. Moreover, this chapter gives an overview of studies and research that have previously been done within the telecom domain that may have an impact on this study. The fifth chapter is one of the results chapters in this report. In this chapter the expected customers and users of Wi-Fi phones are presented. This includes a description of the industries and companies that are expected to benefit from and be interested in Wi-Fi telephony solutions. The user groups section describes the actual users at these companies and their context of use and skills. The next chapter, chapter six, presents the findings from the usability test sessions. This includes findings specifically related to Hitachi WirelessIP5000 as well as its web interface and the PBX. The seventh chapter presents the usability comparison between the three different Wi-Fi phones that have been part of this Master’s project. A summarizing table is found at the end of this chapter. The next chapter, chapter eight, includes analysis of the test results and also proposals of how the usability can be increased. Proposals for each Wi-Fi phone are pre-sented as well as proposals for the PBX or the tele-phony system in general. The ninth chapter consists of a discussion of the results, the proposals and the chosen method. The chapter also includes a discussion of this project’s validity and re-liability as well as proposals for further studies. The chapter is followed by references and appendices. Note that some of the appendices are in Swedish. In the beginning of this report there is a glossary with a list of acronyms and definitions that explain some com-mon terms that have to do with Wi-Fi telephony and telephony in general.

CHAPTER 2. METHOD 3

2. Method This chapter describes the method chosen for attaining the goals of the Master’s project. The chapter covers the literature study and report writing as well as the more practical parts of the project, such as profiling the users of Wi‐Fi telephony and a description of the usability tests and usability comparison between the three Wi‐Fi phones.

2.1 Literature Study A literature study was conducted early in the project, to become acquainted with telephony and usability studies within this field. Since Wi-Fi telephony is rather new, there were problems finding usability studies within this specific field. Instead, I concentrated on finding usability studies that had to do with mobility and mobile phones. Some of the results of these studies are presented in section 4.2.2. In addition to this, I read about telephony and Wi-Fi telephony in general to gain an understanding of Ericsson’s solutions and the technological baseline of this Master’s project. Moreover, I read about human computer interaction and usability studies to be able to perform reliable usability tests. I also read articles about usability related to mental models in large technical system that is partially discussed in section 4.2.4.

2.2 Categorizing Users & Customers One part of this Master’s project was to map the pre-dicted future users and customers of Wi-Fi telephony solutions. To establish this, I performed several in-depth interviews with open-ended questions with key persons from Ericsson Enterprise Sales & Marketing and Ericsson Enterprise Product Management. These interviews concentrated on targeting the users as well as their communications environment and telephony habits. I also studied other communication companies that also offer Wi-Fi telephony solutions, such as Ascom and Cisco. In their sales and marketing material, they give a clear view of the target groups of their Wi-Fi telephony solutions. This was used as an input to my work.

The findings from these studies were used as a foun-dation for the customer and user groups (see chapter 5). This information was used when I recruited participants for the usability tests. The user group descriptions cover what the predicted users and customers of Wi-Fi telephony have in common in terms of working environment, telephony skills, computer access etc. It also presents what the Wi-Fi phone users will use their phones for; what telephony functions are the most common.

2.3 Composition of Test Sessions As previously mentioned, this Master’s project invol-ved usability tests to establish the usability in using the Wi-Fi phone Hitachi WirelessIP5000 connected to MX-ONE. Usability testing was the paradigm used for these tests, partially because the system to be tested is new and is not introduced on the market yet. Based on the user categorization, I prepared the usa-bility test sessions. This included preparing equitable test assignments and finding participants for the tests. The preparations also included installing and configuring the hardware and software in the Ericsson Enterprise Usability Lab for the test sessions. These steps will now be presented more thoroughly. For a more detailed description of the usability tests, see the Test Plan in Appendix A.

2.3.1 Choice of Testing Method Since this Master’s thesis is about a telephony system that has not been released yet, I was limited to perform the usability tests in a laboratory environment testing on an early version of MX-ONE 3.0. The usability tests were only to be performed on Hitachi WirelessIP5000. Ascom i75 and Accton VM1188T were added to the Master’s project at a later stage, and were therefore part of a heuristic

CHAPTER 2. METHOD 4

usability comparative evaluation that is described in chapter seven. As described in the book Handbook of Usability Tes-ting (Rubin 1994), there are four types of usability testing techniques:

(i) exploratory test (ii) assessment test (iii) validation test (iv) comparison test.

Although these tests were performed quite late in the development cycle, I chose to perform an assessment test. The reasons for this was that I did not have a specific objective (required for validation tests) and nothing to compare with at this stage (required for comparison tests) and it was too late for exploratory tests. If the Ascom i75 and Accton VM1188T had been included to the Master’s thesis at an earlier stage, comparison tests had been an appropriate testing technique. Assessment test is the most common type of usability test. In assessment tests the participants are to perform carefully prepared tasks in a laboratory environment while their behavior is being monitored. The goal of the testing sessions was to evaluate whether a Wi-Fi phone wirelessly connected to a MX-ONE PBX is easy to learn and use and satisfying to use and whether the telephony system provides the “utility and functionality that are highly valued by the target population” (Rubin 1994, p 26). More information about the parameters that were measured is presented in the test plan in Appendix A.

2.3.2 Preparing Test Assignments Since I could not test all the functionality, I had to choose a set of tasks for the test sessions that were to reflect the most commonly used telephony functions. I prioritized the functions after usage frequency, meaning that I tested the functions that were normally used the most. The information about what functions that are the most common was based on the Wi-Fi user categorization with information from Ericsson Enterprise Sales and Marketing department that are in close relation to the customers. The first list of tasks was prepared so that the development team at Ericsson Enterprise could establish if the tasks were feasible. These tasks were then rewritten and inserted into the test plan (see Appendix A) and handed to the observers of the test sessions. A new version of the tasks was written that would later be handed to the test participants during the test sessions (see Appendix A). When preparing the assignments for the usability tests, I became aware that certain codes, consisting of numbers and other digits, had to be dialed in order to activate certain functions in the PBX via the Wi-Fi phone. These codes are difficult to memorize but are

necessary in order to fully use the telephony system, using some of the most common functions. For instance, to activate an absence code that indicates that you are on lunch until 12 o’clock, you are to press *23*0*1200#. Other functions are not as complex to activate, such as call back (activated by pressing 5). These functions are however impossible to use without having access to or knowing these codes. This finding is described in further detail in section 6.4.4. I had to adapt the usability tests after this fact, so I decided to let the test participant have access to a quick guide with these PBX codes during the test sessions. The scope of the test was thereby modified and I tried to figure out how the users were to become aware of and get access to these codes. Unfortunately it turned out that not all relevant functions were available when the tests were about to begin. I therefore had to exclude these unavailable functions from the tests. These functions included telephone conferencing, call transfer and parking a call. Instead of these functions, the phone’s web interface could be tested. The test assignments are presented in the test plan found in Appendix A.

2.3.3 Preparing the Usability Lab Fortunately, Ericsson Enterprise had a usability lab with a classic observation room setup, where the user could be situated alone in a test room, and observers monitored his or her behavior from an observation room. Between the test room and the observation room there was one-way mirror. Moreover the participants where filmed by two cameras where one was focused on the Wi-Fi phone and the other caught the participants’ facial expressions and body language. To be able to fully see the phone’s display and what buttons the participants were to press, the Wi-Fi phone had to be stationary during the tests. The phone was therefore glued to the table in the test room, and a headset was attached. Microphones and speakers in both rooms enabled the test participant and observers to communicate, when necessary. All video material was recorded and analyzed further after the test sessions had been conducted. From the observation room we could follow the test participant’s interaction with the phone and see his or her facial expressions. According to Rubin (1994), the testing environment should reflect the actual working environment as much as possible. Since the Wi-Fi phone probably will be used in many different places, the testing environment could not be very adapted. A few props were however added to make the room feel less laboratory-like. The web interface assignment was partially to be carried out in a web browser, and therefore a computer was installed in the test room.

CHAPTER 2. METHOD 5

2.3.4 Finding Participants for the Study In the optimal case, participants from all user groups would have been represented and the tests would be performed in their natural working environment. Be-cause this would require too much time, and the system was not fully functional at the time of the tests, the tests were limited to a laboratory environment where certain target user groups were not represented. In Rubin’s book Usability Testing (1994), he recom-mends to test users with the least experience of the product, although they are not part of the target group. In this case, inexperienced users can not be excluded from the target group; since the user groups are wide, involving experienced as well as inexperienced users (see user group descriptions in section 5.2). According to Rubin, 4-5 participants per subgroup expose 80 % of a product’s or system’s major usability problems. I therefore chose to conduct ten test sessions divided into two subgroups. Since the Wi-Fi phone users will probably be workers with a high on-site mobility (see section 5.2.1), the participants were divided into two groups according to on-site mobility and enterprise telephony experience. The first group consisted of six workers with a high on-site mobility and experience of using wireless enterprise phones. Wi-Fi phones would be suitable for them. Several of the users were currently or previously DECT users. This group of users was recruited from Ericsson Enter-prise from departments that had not been involved in the development of the MX-ONE PBX. The parti-cipants included managers, assistants and technical writers. The other group consisted of four novice users. All though the novice participants use mobile phones and regular phones in their daily lives, they still represented the least experienced users when it comes to using PBX functions from wireless devices such as DECT and Wi-Fi phones. This inexperienced group was recruited among my associates from KTH. Both groups performed the same set of tasks. During the recruiting process I handed out a pretest question-naire in order to map the test participant’s telephony experience and habits. The participants had a wide span in age and professions and consisted of women and men with various backgrounds and telephony habits. It turned out that the mobile workers did not use very many of the available telephony functions. This was consistent with the reports from Ericsson Consumer Lab (2006) presenting that most users do not use advanced telephony functions on a regular basis.

2.3.5 Questionnaires In order to catch the participant’s thoughts and get an understanding of their telephone use and other char-acteristics, several questionnaires were formed. A

screening questionnaire was used during the recruiting process, in order to establish that the participants fitted the target user groups. The questions covered their telephony habits and use of telephony functions. This questionnaire established whether the test person was an experienced or inexperienced user. During the test session, a questionnaire was filled in after the most complex assignments to pick up the participant’s thoughts and comments specifically about that task. Furthermore, a post test session questionnaire with many questions was formed and handed out. This questionnaire sum-marized what the users thought of the telephony system, what they thought needed to be improved. It also gave an insight to their mental model of the telephony system. All questionnaires are found in Appendices B, C and D.

2.4 Conducting the Tests on Hitachi WirelessIP5000 Eight task assignments were tested and each test lasted about an hour. The tests were conducted during a two week period and a maximum of three tests were conducted on the same day. After each day of testing, I summarized the day’s results. During the tests the test participant had access to the Wi-Fi phone Hitachi WirelessIP5000 with a headset, pen, paper, a computer, the phone’s manual, the phone’s web manual, the quick guide with PBX codes and a piece of paper with relevant information that was required in order to manage to perform the tasks. This included phone numbers and user name etc. They received one paper for each task. They also received post-task questionnaires and a questionnaire about the entire test session (see Appendix B, C & D). It was important that the test sessions were as consis-tent and identical as they could be. Therefore, the in-structions were written as a script, which was read aloud to the participants. After each test session, the participant and I had a moment to discuss the test. This was a chance for the participant to comment on and discuss the test session, the Wi-Fi telephony system, the phone and the assignments and it gave me a chance to ask them about their behavior and thoughts. Before the real test sessions were conducted, a pilot test was arranged where the entire system was checked. At this point I verified that the tasks were eligible.

2.4.1 Test Monitoring During the usability tests, several people with different roles were located in the observation room. I worked as a test monitor and administrator, being

CHAPTER 2. METHOD 6

responsible for the administration of the tests as well as the entire test sessions. Before the tests I introduced the participant to the test session and this Master’s project. The participants were informed that they were to be observed and recorded. Furthermore, a video recording operator was respon-sible for recording the tests and adjusting the camera angles. Product and technical experts were also present during some of the test sessions.

2.4.2 Data Collection During the test sessions, various kinds of data were collected, such as which tasks were successful and which were unsuccessful. The problems that had to do with the unsuccessful tasks were noted during the session. Other information concerning the test participant and his or interaction with the Wi-Fi phone was also noted. I noted what went well as well as bad during the test sessions. When guidance was given, this was also noted. All this data was manually collected by writing notes while observing the actual test sessions as well as the recorded tapes. The data from the questionnaire was also used. The time it took for each participant to manage each task was also measured and noted.

2.5 Comparison with Ascom i75 & Accton VM1188T When I started the usability tests on Hitachi WirelessIP5000, it turned out that Ericsson Enterprise wanted to include two other Wi-Fi phones to the scope of the project; Ascom i75 and Accton VM1188T. At this point, it was unfortunately too late to do any changes in the test plan. I however decided to do a usability evaluation on Ascom i75 and Accton VM1188T after the test sessions were over. I

then performed the same tasks as in the usability tests on the other two Wi-Fi phones and compared to the procedures required by Hitachi WirelessIP5000. I analyzed what the test participants found difficult and easy in using Hitachi WirelessIP5000 and checked if it seemed easier or more difficult on Hitachi WirelessIP5000. I also used the heuristic principles and usability parameters presented in sections 4.1.2 and 4.1.3. The results of this comp-arison are presented in chapter seven. Unfortunately there were several functions that could not be tested due to configuration problems. This had primarily to do with Ascom i75, where the software was not released yet. The pre-release version of the software I had access to was incompatible with phone, and the PBX functions could therefore not be evaluated. The phone’s interface including its menu could however be evaluated. Furthermore, in Accton VM1188T, it was for uncertain reasons not possible to activate some of the PBX functions. These functions could therefore not be tested. But since they were related to the PBX, the procedure would differ very little between the different phones. These problems were therefore not considered too limiting.

2.6 Analysis & Report Writing The final phase of the project involved analyzing the results from the usability tests and usability compari-sons and establishing what went well and what needed to be improved. The project also included establishing proposals and recommendations of how the usability of using PBX services via a Wi-Fi phone can be improved. The results of this project are presented in chapter six, seven and eight and were also presented orally at KTH as well as Ericsson Enterprise.

CHAPTER 3. TECHNICAL ASPECTS 7

3. Technical Aspects This chapter presents a short background to telephony, especially Wi‐Fi telephony. The technology baseline of the project is also presented which includes the Ericsson MX‐ONE Telephony System and the Wi‐Fi phones Hitachi’s Wi‐Fi phone IP5000, Ascom i75 and Accton VM1188T. 3.1 Telephony This section presents a brief introduction to telephony systems as well as the basics in IP telephony and Wi-Fi telephony. This information is required in order to understand the technology baseline of this project.

3.1.1 Telephony Systems A very simple telephony system consists of one wire-less telephone, like most of us have in our homes, con-nected to a central node that is connected to the public telephony network. When someone calls, the central node receives the call and forwards it to the telephone placed elsewhere in our home. In large enterprises, the telephony systems are a great deal more complex than this, although the main principle is similar. A typical telephony system can consist of one central node, called Private Branch Exchange (PBX), with hundreds of connections. The PBX serves as a central switch-board for the telephony system connecting all the tele-phones in the network to each other and to the public telephone network. Depending on the type of PBX and network several different services and types of tele-phones (called extensions) can be used. Each type of extension has its pros and cons and is suitable for diffe-rent people. The oldest and most simple type of extension is the analogue extension, which is an ordinary, wired tele-phone. In this type of extension, voice is sent analog-ously to the PBX. The possibilities with analogue ex-tensions are sometimes limited, since they do not always have a display, soft-keys and other functions. There are more possibilities when voice and other data is sent digitally from the phone, which is why analogue extensions are gradually replaced by digital extensions. In digital systems, the system’s intelligence is mostly found in the PBX and not in the telephones. This enables functions like call forwarding and voice mail.

The PBX also controls the telephones’ buttons, lamps and display. But according to Mathiasson and Mälarberg (2001), this is slowly changing back again, as our mobile extensions’ intelligences are increased. Most digital extensions have preprogrammed keys for the most common functions and programmable keys increasing the phone’s flexibility. A disadvantage with regular digital extensions is that they are fixed. When a person leaves his or her desk, she is unreachable. This has opened up for wireless phones, such as mobile extensions and DECT extensions. Mobile extensions are regular mobile phones that you can choose to set as an extension (answering point) in the PBX. After an agreement with the local mobile phone operator is done, the public land mobile network routes all your calls to the PBX that handles all the interaction with the telephone forwarding and routing all your calls to and from this extension. This enables access to features and services in the PBX from a mobile extension. Another type of wireless extension is the so called DECT extension. DECT is a standard for wireless telephony that was developed in 1992 by the European Telecommunications Standards Institute (ETSI). DECT extensions are common in enterprises, and most of the wireless telephones for home users are also using the DECT standard. In enterprise solutions, a DECT exten-sion wirelessly connects to an access point placed within 300 meters. The access point is connected to the PBX, and forwards the calls to and from the DECT extension. DECT phones are common among users who move around to a large extent on the office premises. Since the DECT phone only works within the office building, supervisors know that the employees do not use the telephones when they have left work or its immediate vicinity. A telephony system consists of a large network of tele-phone cables that are connected to the PBX and every


room with a telephone. If wireless solutions like DECT and Mobile Extensions are to be used, access points have to be set up enabling coverage all over the buil-ding. In addition to this, almost all enterprises have a data network enabling network and Internet access. The result is two completely separate, but parallel, sys-tems for telephony and data communication. IP tele-phony offers a solution to this, making the telephone cables unnecessary.

3.1.2 IP Telephony IP telephony is a technology for transmitting voice over an IP network. IP telephones (IP extensions) are connected to a LAN that connects to the PBX using the Internet Protocol (IP). This technology combines the LAN and telephone infrastructure to one system, which enables new communication possibilities and services. Mathiasson and Mälarberg (2001) predict that the IP networks will be used for almost all communication in the future. IP telephony can be carried out on IP telephones or on a computer based interface. Telephony on a computer opens up for possibilities to increase the usability by making it easier to use advanced telephony services and also include new features; such as seeing the status (busy, on the phone, away) of all your friends or colleagues (Cadiz et al. 2004), such as in Skype. Since IP networks are packed-switched, the data has to be split into packets to be transmitted disjointedly to the receiver. Lost, delayed and damaged packets are therefore rather common in IP networks. This makes error detection and correction very important. This is especially important when it is absolutely necessary that all data is delivered. Voice communication is, however, very time sensitive, since delays in phone calls tend to be very bothersome for both parts. To optimize transport of voice over LANs, a special collection of protocols, named Voice over IP (VoIP) has been formed.

3.1.2.1 Voice over IP (VoIP) VoIP is a set of standards that instead of prioritizing effectiveness by minimizing overhead, as in typical IP communication, prioritizes packets arriving within certain time frames. VoIP packets are therefore smaller and have higher priority than data packets. In addition to this, VoIP includes advanced error detection and correction systems to ensure a high quality of service (QoS). VoIP also includes protocols for voice digitali-zation and noise suppression as well as special algo-rithms for compression and error checking. The pack-ets include information about the destination, sequence number and information for error checking. At the re-

ceiver the packets are decompressed and put in the rig-ht order, using a buffer. Signaling protocols are used for establishing virtual circuits over the network between two phones that the media stream uses. Examples of such protocols are H.323 and SIP, which will now be introduced more thoroughly.

3.1.2.2 H.323 The H.323 standard was developed by the International Telecommunication Union (ITU-T) in 1996. It consists of recommendations for packet-based multimedia com-munication, enabling telephones in the public network to talk to computers connected to the Internet. H.323 reuses many of the standards used in traditional telephony networks.

3.1.2.3 Session Initiation Protocol (SIP) The Session Initiation Protocol was developed in 1999 by the Internet Engineering Task Force (IETF). It uses text based syntax similar to HTTP and connects the clients and servers using the Internet Protocols TCP and UDP, aiming for Internet to be used as a telephone network. SIP makes it possible to integrate e-mail, web, conferencing and other Internet Services. It also makes it possible to use any phone and have the same tele-phone number.

3.1.3 Wi‐Fi Telephony Wi-Fi telephony is a technology that combines the infrastructure convergence benefits from IP telephony and the mobility that DECT extensions offer. Wi-Fi phones communicate with a PBX wirelessly, using a wireless, IP-based network (WLAN). The system uses the WLAN standard collection 802.11 formed by the Institute of Electrical and Electronics Engineers (IEEE) in 1997. Each Wi-Fi phone has a network interface card (NIC) that communicates with an access point. The access points are connected to an IP PBX. In “good” environ-ments, where nothing interferes with the radio traffic, Wi-Fi phones work well. Big machines and portable containers in for instance warehouses and industry sites can however cause interference since the radio cove-rage area is constantly changed. Other devices, using the same frequencies, can also interrupt the Wi-Fi transmissions since it is carried out on open fre-quencies that other devices also use. At Ericsson Enterprise, many believe that Wi-Fi grad-ually will replace DECT (Höglander 2006; Junthé 2006). One of the main reasons for this is that DECT is perceived as an old system and that more and more ent-


erprises are interested in IP solutions to save expenses and be able to combine voice and data using only one system. For instance, Wi-Fi phones open up for com-bining telephones with other gadgets, such as bar code readers, scanners and PDA:s. This is welcomed by many workers. According to Ericsson’s Consumer and Enterprise Lab (2006), 30 % of the working people would appreciate using one tool for many things. In the first step, however, Wi-Fi phones will simply be an alternative to DECT phones and other wireless phones. Combinations of different gadgets will probably be available in a couple of years. Existing wireless networks for data communication can be used for IP telephony, which can save expenses. In many cases, however, the networks have to be upgra-ded to suite VoIP communication. For instance, time gaps and delays have to be prevented. In some areas, such as conference rooms and receptions, the capacity has to be increased enabling many simultaneous phone calls. Wi-Fi telephony can in some cases be 50-60 % more expensive than DECT (Höglander 2006) partially because the market is not mature yet. But Wi-Fi is considered a more long term investment than DECT and other telephony solutions, and once Wi-Fi phones

will be more available to and interesting for home users and volumes go up, prices will probably drop. The convergence between the data network and tele-phony system that Wi-Fi telephony offers, makes it possible to use the same infrastructure for both systems and one department (preferably the IT department) can be responsible for all communication, with no need for specially trained DECT administrators. This conver-gence also makes it possible to access network resour-ces from your telephones, enabling a higher mobility and flexibility. A large practical issue with Wi-Fi phones today, is the short battery time. Sleep mode can possibly solve this, but there are problems due to the large number of ac-cess points that the telephone constantly communicates with. Further problems that have to do with usability are presented later in this report.

3.2 Technological Baseline The technology that was used in this Master’s project was the Ericsson MX-ONE system, with an IP PBX and the three Wi-Fi phones Hitachi WirelessIP5000,

Figure 1. An overview of a MX-ONE telephony system (Ericsson Enterprise, 2006)


Ascom i75 and Accton VM1188T. These will now be presented more thoroughly.

3.2.1 Ericsson MX‐ONE System Ericsson MX-ONE is a server-based telephony system that was released in 2004 and has been re-released several times with new functionality. Today MX-ONE can integrate many different types of extensions and types of media. Voice, text and in some cases video can be transferred between mobile phones, fixed digital phones, IP phones and with the new version, MX-ONE 3.0, also Wi-Fi phones. The possibilities depend on the chosen software and hardware, but the MX-ONE Tele-phony System was designed for effectively handling VoIP. The system that was evaluated in this study in-cluded an MX-ONE IP PBX. Figure 1 (see previous page) shows an overview of a MX-ONE telephony system. All the intelligence in an MX-ONE Telephony System is currently in the PBX, which forwards incoming calls to the different types of extensions and routes the out-going calls. As a result, the caller does not notice the different types of extensions. Contacting a Wi-Fi phone is just like contacting any other type of extension. The caller therefore does not need to know the location of the telephone and the user can change the type of ext-ension back and forth and still have the same telephone number. The same services and features should be available to all users, regardless of extension type. But this is not always the case since the possibilities are limited by each extension’s functionality and intelligence. More-over, usability aspects limit the possibilities since it for instance is very tricky to interact with a PBX using a wired telephone without a display, compared to using a digital extension with display and specific buttons for each command. As of today, Ericsson Enterprise does not develop any Wi-Fi phones. Instead, they certify Wi-Fi phones from other vendors as suitable for MX-ONE. This project compares three different Wi-Fi phones that may be certified by Ericsson.

3.2.2 Wi‐Fi Phones Wi-Fi phones are phones that use the WLAN standard IEEE 802.11b/g. To be able to communicate with Ericsson’s MX-ONE system, the phone has to use the SIP or H.323 protocol. These protocols do not control the keys and what is shown on the display, except for whose calling. Instead, the PBX uses the WAP protocol to control the soft keys and other information. But to be fully functional, the SIP protocol has to be used to a greater extent in the interaction between the

MX-ONE PBX and Wi-Fi phones (Avesand 2006). This will probably be the case for future releases of MX-ONE, which will increase the telephony system’s usability. Today, much interaction is preformed by entering number combinations. In this Master’s thesis I analyzed the usability in three Wi-Fi phones; Hitachi WirelessIP5000, Ascom i75 and Accton VM1188T, with special focus on Hitachi WirelessIP5000.

3.2.2.1 Hitachi WirelessIP5000 Hitachi WirelessIP5000 is a Wi-Fi phone that via an access point can connect to a MX-ONE IP PBX. This phone looks like a regular mobile phone (see figure 2 on the next page) with a monochrome display but uses WLAN technology instead of GSM or 3G. The SIP protocol is used for the communication between the phone and the PBX. Hitachi WirelessIP5000 has a display that can handle 8 lines of text with 10 digits on each line. Apart from the number keys and * and #, there are five functional keys:

(i) Start call (ii) Hang up (iii) Clear (iv) Two soft keys

The round multi-function key can be pressed up, down, left, right and enter. The function of the soft keys is context sensitive and shown in the display immediately above the keys. Hitachi WirelessIP5000 can store 200 addresses and it has a vibrating alert for phone calls and for instant me-ssages. This messaging feature will however not be po-ssible when connecting the telephone to the MX-ONE system. Another feature that Hitachi WirelessIP5000 usually handles, but is not supported by MX-ONE, is the possibility to see the presence of other Wi-Fi phone users in the network. The telephone comes with an USB slot and cable that is used for charging the telephone, uploading files, edi-ting the address book etc. It also has a management programmed that can be used by telephone admini-strators to configure the telephone and its connections with the access points and the MX-ONE PBX. Hitachi WirelessIP5000 uses standards such as WEP and IEEE 802.1X, to ensure a high security level.

3.2.2.2 Ascom i75 Ascom i75 is a Wi-Fi phone that can be connected to a MX-ONE IP PBX using the SIP protocol. A photo of


Figure 2. Hitachi WirelessIP5000 Figure 3. Ascom i75 Figure 4. Accton VM1188T

From: www.wirelessip5000.com From: www.ascom.com From: www.accton.com

the phone is found in figure 3. The phone has a mono-chrome display and is equipped with 22 buttons. Apart from the number keys and * and #, there are six func-tional keys:

(i) Start call (ii) Hang up (iii) Up (iv) Down (v) Left (vi) Right.

Furthermore, Ascom i75 has 3 programmable soft keys, located below the display. The phone also has an alarm button that is located on the top of the phone. The dis-play is immersed into the phone, to protect the display from scratches. In the marketing material from Ascom, it is clear that the phone is adapted to a specific target group; workers in the health care industry as well as heavy industries and retail. The phone is equipped with a hinge type clip that can be used to fasten the phone onto a belt or pocket. The functionality in the phone includes a message function, a call list and a phone book that can store 100 phone book entries. The call list feature stores the latest 20 calls. Unfortunately, the message function is not sup-ported by MX-ONE. The telephone operates in 11 languages; Danish, Dutch, English, Finnish, German, Italian, Norwegian, Portuguese, Spanish and Swedish.

Ascom i75 is available in a medical edition, for hosp-ital staff. This edition is equipped with several different types of alarms that can inform other parts of the staff in case of emergency. The phone is compatible with many clinical and nurse alarm systems.

3.2.2.3 Accton VM1188T Accton VM1188T is a Wi-Fi phone that can connect to MX-ONE 3.0. The phone allows, according to Accton’s sales material, users to make VoIP calls at work, home and on campus. A picture of Accton VM1188T is shown in figure 4.

Accton VM1188T uses the SIP protocol to com-municate with the PBX. In contrast to Ascom i75 and Hitachi WirelessIP5000, Accton VM1188T, has a color display. The phone has other features, such as calculator, clock alarm, multiple ringing tones, vibrating alert, speaker phone, call list, etc. Like the other Wi-Fi phones, Accton VM1188T also has a phone book that can store phone numbers and e-mail addresses. The phone has a built in forwarding feature that can forward all calls to another extension or phone number. Apart from the number keys and * and #, Accton VM1188T has a joy stick and 4 functional keys:

(i) Start call (ii) Hang up (iii) 2 soft keys.

The joystick can be pushed to all directions, and also acts as an enter button.

CHAPTER 4. THEORY 12

4. Theory The following chapter briefly presents theories of Human Computer Interaction and Usability and how they can be applied to this study. First a theoretical framework of Human Computer Interaction will be given that explains what usability is. Secondly, previous research and relevant usability studies within the telephony domain will be presented.

4.1 Usability & Human Computer Interaction Theory Usability can be interpreted and defined in many different ways. The International Standards Organiza-tion (ISO) defines usability as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satis-faction in a specified context of use” (ISO 9241-11). ISO defines these terms as;

Effectiveness: “the accuracy and completeness with which users achieve specified goals.” Efficiency: “the resources expended in relation to the accuracy and completeness with which users achieve goals” Satisfaction: “freedom from discomfort, and positive attitude to the use of the product.” Context of use: “characteristics of the users, tasks and the organizational and physical environment.”

According to Faulkner (1998, p 1), Human Computer Interaction (HCI) is “the study of relationships which exist between human users and computer systems they use in their performance of their various tasks.” This definition explicates that HCI concentrates on the interaction between the users and the system and the goal is to improve this interaction. The system should be adapted to the users’ capabilities, in terms of memory, vision and cognition etc, to make it easier for the user. As a result, HCI has to do with usability to a large extent. When analyzing these definitions of usability and HCI, it becomes clear that a system or device is developed for the users and should therefore be adapted to the users’ needs, capabilities, limitations, skills, character-istics, habits and contexts of use. By analyzing and un-derstanding the users, it is possible to improve the in-teraction between them and the system, resulting in a

higher efficiency and user satisfaction. The system should be developed with a user focus, where the users do not only interact with the final system but also play a part in the development process. The goal is to dev-elop a system that is “easy, effective and enjoyable to use – from the users’ perspective” (Preece et al. 2002, p 2). A usable system has plenty of advantages compared to systems with lower usability. Not only is the interac-tion more satisfying for the users, it also saves costs. Computer system training and support is expensive. Usability, moreover, supports a higher productivity. A system with a high usability will therefore in the most cases be the least expensive alternative in the long run. It can also prevent the users from making tremendous or small mistakes and saves the users from frustration from lacking usability. According to Faulkner (1998), many users know what they want to do but lack in knowledge of computer systems, which limits them. If a system is designed with HCI and usability in mind, knowledge of the system should not be required. The user should be able to focus on the task he or she wants to perform, and not be distracted or confused by the system. This belief is similar to Norman’s (2002) conception that good design means that users can figure out what to do and that the user can tell what is going on. The goal with HCI; making systems easier to use, may seem rather apparent. But most systems are designed without input from the actual users. Moreover, if the users are kept in mind, Faulkner (1998) believes that there is a tendency of wanting to design for all and the-refore making too big generalizations. As a result, the system is designed for no-one specifically.


4.1.1 Understanding the Users Since usability and HCI have to do with the users’ wants and needs, it is necessary to have a good understanding of the actual users. Apart from knowing who the users actually are, it is important to map their context of use and levels of performance. It is however impossible to map every individual – generalization is essential. These generalizations, based on characteristics of the targeted users, should neither be too wide nor too narrow. It is also important that these characteristics are based on input from the users or reliable facts and statistics and not prejudice.

4.1.2 Usability Goals & User Experience Goals When evaluating a system’s or device’ usability it is difficult to know what to measure and how to measure it. Different usability preachers promote different met-hods and different goals of usability. Preece et al. (2002) believe that, to be considered usable, a system should be:

(i) Effective (ii) Efficient to use (iii) Safe to use (iv) Have good utility (v) Easy to learn (vi) Easy to remember how to use.

This means that the system should be adapted to what it is supposed to do and satisfies the users’ goals. Preece et al. (2002) also present a new dimension to usability by introducing 10 user experience goals that should be fulfilled for a device to be considered having high usability:

(i) Satisfying (ii) Enjoyable (iii) Fun (iv) Entertaining (v) Helpful (vi) Motivating (vii) Aesthetically pleasing (viii) Supportive of creativity (ix) Rewarding (x) Emotionally fulfilling.

These parameters have been used as a foundation for the usability evaluation of the MX-ONE telephony system in this Master’s project.

4.1.3 Heuristics & Heuristic Principles Heuristic evaluation is a method where the usability is assessed by evaluators or experts that base their judg-ments on certain usability principles. The usability expert Jakob Nielsen (1993) developed these principles

based on the experience he had gathered from evalua-ting many different kinds of interfaces. The heuristic principles or parameters are presented below:

(i) Visibility of system status (ii) Match between system and real world (iii) User control and freedom (iv) Consistency and standards (v) Error prevention (vi) Recognition rather than recall (vii) Flexibility and efficiency in use (viii) Aesthetic and minimalist design (ix) Help users recognize, diagnose and

recover from errors (x) Help and documentation

These parameters, together with the usability goals presented above, were used as a benchmark in the usability comparison of the three different Wi-Fi phones and their interaction with MX-ONE (see chapter seven).

4.1.4 Usability Evaluation Techniques Evaluation of a device’s or system’s usability can be done in several different ways. According to Preece et al. (2002), there are four different evaluation paradigms;

(i) “Quick and Dirty” (ii) Usability testing (iii) Field studies (iv) Predictive study

Preece et al. (2002) have also introduced five evaluation techniques;

(i) Observing users (ii) Asking users (iii) Asking experts (iv) User testing (v) Modeling users’ task performance.

Usability testing, which was used in this project, is per-formed in a laboratory where typical users perform certain well prepared tasks that are typical for the pro-duct or system. The participants are observed and all actions, such as expressions and key presses, are rec-orded on video to be further analyzed later. When eval-uating the system, the number of errors and the time it takes to perform a certain task are measured. The focus will be on the user testing technique, but interviews or questionnaires might be used for measuring the users’ satisfaction.


4.2 Study of Similar Research Considerable research has been done on usability of phones, but not necessarily on Wi-Fi phones. I have therefore concentrated on finding usability studies in related domains such as telephony, mobility and large technical systems as well as the use of advanced telephony services. Telephones have been used for very long now, and today there are many different types; desktop phones, wireless phones and mobile phones, just to mention a few. All these types of telephones have different func-tions that are often activated or used in different ways. The wired telephone perhaps has buttons for telephony functions while the mobile phone uses a menu system accessed with navigational buttons. This can cause unnecessary confusion for the telephone users. Other complications have arisen technical devices have be-come smaller and smaller while the complexity has increased. I have chosen to summarize some of the most relevant studies that were used as a foundation for my work.

4.2.1 General Telephone Usability There have been many usability studies about telephones and telephony systems. Many of them are about the difficulty in using the many functions found in our phones today and how they can be redesigned to make it easier for the users. People tend to avoid using features and services that they find too complicated (Cadiz et al. 2004). In this case though, with wireless IP telephony, the users are using the telephone in their work and are expected to be able to perform certain tasks on the phone to be reachable and be able to com-municate in an appropriate manner. Many enterprises have telephony guidelines that, for instance, require the employees to enter absence messages on their phones when they leave for lunch or for the day. Apparently this can lead to usability hazards for the users, but according to Cecilia Bingert (2003), a useful function that is difficult to use is more popular than a function that is easy to use but does not accomplish anything useful.

4.2.1.1 Reasons for Lacking Usability Mobile telephones are typical examples of devices where the technology and features have become more and more advanced and the target group is very wide expecting everyone to be able to handle them. Heterogeneous target groups are typical for most telephones and telephony systems, which is one of the reasons why many consider telephones having lacking usability.

Donald Norman (2002) presents several telephony usability problems in his classic The Design of Everyday Things, which exemplifies the general lack in telephony usability. In the beginning of his book he states that “new telephone systems have proven to be [another] excellent example of incomprehensible design.” (Norman 2002, p 6). Most target groups span in age, preferences, telephony and technology skills. Since the telephones are not adapted to one specific target group’s demands and limitations, a design-for-all concept is used. Bill Clark (2005), research director at Gartner, has done research about failures in the wire-less industry, and believes this design-for-all concept can not be used for wireless applications. To be suc-cessful, Clark (2005) believes that these narrow kinds of applications have to be optimized for a certain user group. Not only are the target groups heterogeneous, so are the contexts in which different telephony systems are to be used. One single phone is supposed to work well in loud as well as quite environments, in dark as well as light, hot and cold. Furthermore, the users may use the phones for many different things doing other, varying things simultaneously that may interrupt the interaction with the phone. Most mobile technologies available on the market are designed and adapted to the expert mobile users and not the regular users. This was one of Jacqueline Brodie’s and Mark Perry’s (2001) findings in their study of the communication and collaboration needs of Blue-Collar Workers. They therefore believed that these workers needed mobile technologies that were adapted specifically to them and their communicative needs. To establish their needs, 15 blue collar-workers were studied with fieldwork investigation and unstructured, contextual interviews. Moreover, Fallman’s (2002) studies have shown that most mobile devices are developed as extensions to the office desk for office workers, which has resulted in products not suited for other user groups, such as industry workers. Fallman (2002) believes that to be able to design a mobile device for a certain user group, one has to learn about that group and their context of use. The Wi-Fi phone user groups are presented in section 5.2 in this report. Apart from the heterogeneous target groups and contexts of use, the general lack of usability in telephones have to do with things mainly related to the many and advanced functions to be performed on a small device with few buttons and sometimes a small display. Since the number of buttons is limited on most phones, many functions are activated by dialing long number combinations. This leads to a lack of visibility


and natural mapping. These number combinations are difficult to learn and remember. According to Norman (2002), most users do not even know how to use the R and # buttons found on most wired phones. To be able to use the functions on the telephone, the user has to memorize the number combinations, which is very de-manding, especially since there are no visual reminders. This is an issue especially in older phones without dis-plays, but it is evident that reminders and natural map-ping increases the usability in almost all devices and should be used to a greater extent.

4.2.1.2 Need of Mapping Norman believes that a device is easy to use “when there is visibility to the set of possible actions, where the controls and displays exploit natural mapping” (Norman 2002, p 25). Mapping has to do with the re-lationship between a device’s controls and their actual effects. A button without any label has lacking map-ping, in contrast to a button with an up-pointing arrow at an elevator. When designing buttons and interfaces for new devices, one should adapt them to physical an-alogies and cultural standards.

4.2.1.3 Need of Consistency Users can become familiar with systems, over time adapting their behavior to it. If such a product is upgraded or replaced, it is, according to Faulkner (1998), important to keep the previous system in mind. The users should in these cases not be required to learn totally different ways of interacting with the new sys-tem. To make it easier for the users, a new telephony system should therefore work like the users expect it to. This is in line with Norman’s (2002) belief that words used in the telephone should relate to words that the users know of, which is probably terminology found in previous telephones and telephony systems that the users have been in contact with.

4.2.1.4 Need of Feedback Another explanation to the general lack in usability among telephones and telephony systems is insufficient feedback. Most telephones have an unused capacity for generating tactile, sound and text feedback. According to Norman (2002), plenty of time, money and energy were spent on feedback when the fist telephones were developed by Bell Telephone Laboratories. In these early phones there was, for instance, tactile as well as sound feedback for every button that was pressed. Today’s phones are almost the opposite, where the phones are cheaper and have increased functionality and have less feedback (Norman 2002). The new tech-nology should make it easier for the user, instead of the other way around. The display, for instance, found on

most phones today, can be used for instructions to the user (Norman 2002).

4.2.2 Usability in Mobile Devices According to Gorlenko and Merrick (2003) there are major usability differences between mobile devices and stationary devices. This difference has to do with the varying environments and situations that the devices are used in. In order to develop a user friendly, mobile device, these differences should be taken into account. A major difference between mobile and stationary de-vices is that mobile devices are often used while the users focus their attention on something else. The need for input and interaction with the telephone should therefore be limited. This means that the usability of these mobile devices should be high and interaction should be designed to distract the user as little as pos-sible. Another difference is that mobile telephones are carried around, so the user does not have to go any-where to use the phone. Furthermore, the mobile devi-ces are often small with small displays. Luca Chittaro and Paolo Dal Cin from the Human Computer Interaction Laboratory at the University of Udine in Italy evaluated two WAP user interface cho-ices to establish which one was the most user-friendly. In the article they present the general principle, that potentially dangerous actions require a confirmation from the users.

4.2.3 Usability in Small Devices As I previously mentioned, one cause of the usability issues found in many telephones is that devices often are small but very complex. Many users can, however, see the advantages of having small phones and there-fore oversee some of the complications that this causes. Minhee Chae and Jinwoo Kim at the Human Computer Interaction Laboratory at Yonsei University in Korea in 2004, performed usability tests in a controlled lab environment, to establish how the usability of WAP phones is affected by screen size and information struc-ture. The study was based on the conception that, since mobile phones can only display a limited number of characters, the users have to scroll and perform mult-iple key presses which probably lead to navigation err-ors and a low usability. Conclusions of their work was that there was a big usability difference between displays handling three and six lines of text and that information depth and width should be adapted to the users’ screens.


4.2.4 Large Technical Systems & Mental Models As previously mentioned, the usability aspects of wire-less IP telephony are many, since we are dealing with a large, technical system that includes telephones, a PBX and access points etc. In 2002, Leysia Palen from the University of Colorado and Marilyn Salzman from Salzman Consulting per-formed a telephony usability study that was based on the difficulties in interacting with larger systems where many different components are joined. The study was named; Beyond the Handset: Designing for Wireless Communications Usability. It was based on several in-depth open interviews with 19 novice wireless phone users and the users kept voice mail diaries that gene-rated a naturalistic observation of the users using their wireless phone. Palen and Salzman believed that “opportunities for usability problems [therefore] scale beyond the handset” (Palen & Salzman 2002, p 125). As in this Master’s project, the authors consider the telephone handset to be an “an interface to so much more than another person on the phone line” (Palen & Salzman 2002, p 126). They therefore believed that the technology should be treated as a system. Their study concluded that novice mobile users “struggle to under-stand how the larger technological system worked” (Palen & Salzman 2002, p 126) trying to build a mental picture of the mobile telephony system. They found that many users’ problems outside their handsets, such as poor signal coverage, were associated with the handset; because the users could not make a proper distinction between the different system components and related everything to the components that they could identify. Another finding in the study was that problematic hardware and software design discouraged the users to explore the phones. This resulted in the users not using their telephone book, volume control etc. Palen and Salzman also found that, since the users are not in direct contact with the mobile telephony net-work, it is difficult for them to diagnose and under-stand it, resulting in an “incorrect” mental picture. The users for instance expected the mobile phones to funct-ion like their regular phones or like walkie-talkie radios. Norman (2002) refers to this mental picture as the user’s mental model which is often separated from the design model; the designer’s conceptual model. When having an incorrect model, Norman believes that the user meets many difficulties using the phone. Optimally, the users’ mental model of the system equ-als the designers’ model. If this were the case, Norman (2002) believed that the users would know what do and do it in the intended, most effective, way. This is back-

ed up by Preece et al. (2002), who believe that “if peo-ple could develop better mental models of interactive systems, they would be in a better position to know how to carry out their tasks efficiently and what to do...” (Preece et al. 2002, p 94). It is however important to clarify that a user with an incorrect mental model, should not be blamed. According to van der Veer and Melguizo (2002), users often develop mental models based on previous knowledge and systems that they have been in contact with. This may lead to incorrect mental models if the new system does not function similarly. Preece et al. (2002) suggest that the system should be made more transparent or to educate the users so that their mental model gets more correct. The trans-parency can be increased by providing useful feedback, clear instructions and having intuitive ways of inter-acting with the system as well as providing context sensitive guidance (Preece et al. 2002). Furthermore, terminology and grouping of menus and functions should match the user’s expectations. A correct mental model enables interaction with high usability (Veer, van der. & Melguizo 2002).

4.2.5 Wi‐Fi telephony Studies I have found two studies about Wi-Fi studies. None of these concentrated on usability aspects, but they are still worth mentioning.

4.2.5.1 Riksgäldskontoret A couple of years ago, Cisco Systems’ Wi-Fi tele-phony system was installed for evaluation in the Swedish government authority “Riksgäldskontoret”. This authority has 140 employees working in the Stockholm office. Wireless IP phones were considered interesting for this authority, since many of their employees move around in the building. Riksgälds-kontoret’s IT department, that evaluated the system, found that the Wi-Fi phones did not have enough battery capacity and that the company telephone register could not be reached. The security aspects were also lacking (Grufman 2005).

4.2.5.2 Socialtjänsten in Umeå In February 2004 a Cisco Systems Wi-Fi telephony system was installed in “Socialtjänstens Hus” in Umeå in Sweden. The findings of this system, was that the quality of service was lacking, due to problems with covering the entire 4000 square meter building with over 220 users (Grufman 2005). Problems with stut-tering audio and dropped calls made the system dis-satisfactory. The number of access nodes had to be in-creased but there were still problems with too many simultaneous calls and further upgrading was necessary.

CHAPTER 5. CUSTOMER & USER CATEGORIES 17

5. Customer & User Groups The following chapter is the first part of the results chapters in this report. In this chapter the customer and user groups are presented. The chapter begins with a description of the customers of Wi‐Fi telephony. Secondly the expected users of Wi‐Fi phones are presented, as well as the most common telephony functions. 5.1 Wi‐Fi Telephony System Customer Groups Regarding Wi-Fi phones, it is important to make a separation between the customers, who are buying the solution, and the users, who will be using the product. In some cases, especially in smaller enterprises, these two groups overlap; the users buy their own telephones. But in larger enterprises with more complex telephony solutions, perhaps including a MX-ONE 3.0 IP PBX, this is mostly not the case. In this section, the predicted customer enterprises of the MX-ONE 3.0 Wi-Fi tele-phony system are presented. In the next section, there is a description of the predicted actual users. The information for this section is gathered from inter-views with people from Ericsson Enterprise Product Management as well as Ericsson Enterprise Sales and Marketing Department. Research from Ericsson’s Con-sumer and Enterprise Lab has also been used. Other telecom companies, such as Cisco Systems and Ascom, offer Wi-Fi telephony solutions similar to Ericsson Enterprise’ solution. Apparently, most of them are tar-geting the same type of customers and users, and I have therefore been able to use their sales material and user profiling as input material for this section.

5.1.1 Wi‐Fi Customer Groups Large enterprises, with at least 100 employees, and a mobile work force will be the largest Wi-Fi customer groups (Höglander 2006; Junthé 2006; Berggren 2006). This includes industries, logistics enterprises and large, technological enterprises. Governmental institutions are also a customer group of interest. In a couple of years, when the technology has become more robust and stable, hospitals will probably also be interested of Wi-Fi technology. In Cisco System’s marketing mater-ial, they list the industries that can benefit the most from Wi-Fi telephony systems (Cisco Systems 2006); Education, Financial services, Government, Healthcare,

Hospitality, Manufacturing, Retail and Transportation. These customer groups are very similar to the customer groups that were predicted by Ericsson Enterprise. To summarize my findings, I have chosen to present the major target customer groups of Wi-Fi telephony solutions.

5.1.1.1 Education Institutions The education industry is one of Cisco Systems’ major customer groups (Cisco Systems 2006) that was not highlighted during my interviews with employees at Ericsson Enterprise. Educational institutions, however, often have a very mobile workforce that moves inside the school buildings and on campuses. Using wireless telephony, such as Wi-Fi telephony, staff all over the campus is able to communicate instantly. In 2005, Nortel installed a Wi-Fi telephony system at Coppin State University (Nortel 2005a). Not only did the system offer wireless internet connectivity through-out the campus, it also enabled faculty, campus secur-ity and administrative staff to communicate wirelessly with Wi-Fi phones (Nortel 2005a).

5.1.1.2 Financial Services Financial firms, such as banks, were also presented as a major customer group in Cisco Systems’ marketing material. Cisco Systems believes (2006) that a wireless IP telephony system can be used for instantly accessing resources such as customer data and financial data. Always being reachable is also an important factor in this often so time critical sector (SpectraLink 2005). According to IDC’s market research about mobility and communication, security is a major concern in this innovative industry (IDC 2003). Today, much in-formation is exchanged using laptops. Further tech-nological advancement could make it possible to ex-change and access this information using a PDA (IDC

CHAPTER 5. CUSTOMER & USER GROUPS 18

2003) which can be combined with voice communica-tion.

5.1.1.3 Government In Cisco System’s marketing material, governmental institutions and authorities are presented as a target group for Wi-Fi telephony (Cisco Systems 2005). The reason for this is that governmental institutions often have a mobile workforce that needs to be able to res-pond quickly to crises as well as day-to-day operations (Cisco Systems 2005). Today, many people employed by the government use mobile phones, which has been shown to increase their efficiency (IDC 2003).

5.1.1.4 Healthcare One major DECT customer group is hospitals where nurses, doctors and janitors move around to a considerable extent on the hospital premises (Höglander 2006; Junthé 2006; Berggren 2006). But hospitals are generally afraid of radio interference and tend to be rather late in adopting new technology (Junthé 2006). Hospitals will therefore probably not be one of the first Wi-Fi customers. They will however, be one of the major customer groups in a couple of years (Höglander 2006; Junthé 2006). A reason for this is that the staff is very mobile. By installing a wireless telephony system, such as DECT or Wi-Fi, the staff can be reached regardless of where in the building they are located and paging and traveling times are eliminated. In 1995 at a typical nursing unit, 58 min-utes a day was spent by nurses traveling to answer the phone (SpectraLink 2004). At the Wi-Fi business dev-elopment summit in 2005, Keith Jones from Daconi sp-oke about installing Wi-Fi communication in hospitals. According to him, hospitals can benefit greatly from Wi-Fi telephony, since the staff is very mobile. But since the staffs often are big and altering, partly due to working in shifts, telephony training is not very com-mon (Jones 2005). Consequently, the Wi-Fi phones have to be very easy to use (Jones 2005). Queen Margaret Hospital in Scotland installed a DECT telephony system in order to be able to reach key medi-cal staff (Friday 2002). Evaluations showed that 96 % of the users believed that the new wireless telephony system had resulted in more time with patients and im-proved patient care (Friday 2002).

5.1.1.5 Hospitality The hospitality industry including hotels, restaurants, catering, can also benefit from Wi-Fi telephony sol-utions. By constantly being reachable, the staff can offer a high responsiveness and customer service. In the hotel sector, for instance, the same WLAN that the staff uses for telephony can be used by guest for ac-

cessing the internet from the entire hotel complex. The staff can also quickly respond to customers’ requests since they can easily contact the right employee. Using Wi-Fi telephony, the need for mobile phones and pag-ers, that were previously common in this sector, is eli-minated.

5.1.1.6 Large Technical Enterprises Large technological companies are another probable large target group for Wi-Fi telephony systems, partly because they often are early adopters of new tech-nology (Junthé 2006). Many large technical enterprises were early in installing wireless networks and want to benefit from the convergence possibilities (Berggren 2006).

5.1.1.7 Manufacturing and Construction Manufacturing and Construction are two industries that can benefit from wireless IP solutions and are probable early adopters of this technology (Höglander 2006; Kung 2005; Berggren 2006). A Wi-Fi telephony sys-tem can make factories respond faster to changes and disturbances in demand, orders (such as quantity) as well as machine breakdown and software errors (Ascom 2005b). This opens up for increased supply chain integration and management where the supply chain becomes more effective and efficient in meeting the demands of the end users. Increased supply chain integration, where communication is an essential foun-dation, enables customization of products and services. Moreover, wireless telephony makes it possible for managers to be in contact with the staff as well as sup-pliers and customers regardless of his or her location. Since maintenance personnel and external support offi-ces always can be reached, production downtime can be minimized (SpectraLink 2005). Apparently, tech-nicians spend about 39 minutes a day traveling to a phone to answer a page (SpectraLink 2004) Beyh and Kagioglou did a study in 2004 about inte-gration of IP telephony in construction site communi-cation. The communication goal was to have a system that could be used for data exchange between field operation and the field office, often placed in a trailer nearby (Beyh & Kagioglou 2004). Apparently, im-proved efficiency can be reached if designers, suppliers and construction managers can easily communicate and the field operation easily can contact remote experts. According to Beyh and Kagioglou (2004), most con-struction sites currently use a DECT system and some use other technologies, such as the GSM network. By switching to a Wi-Fi telephony system, a higher trans-mission rate can be used; although more access points


are needed in order to establish a coverage equivalent to a DECT telephony system.

5.1.1.8 Retail The retail industry is probably interested in the pos-sibilities that Wi-Fi telephony offers (Cisco System 2005; Höglander 2006; Junthé 2006). By being accessible through out the building, the employers can help customers regardless of their location. According to Frank Bulk (2005), retail stores can double their ef-fectiveness by adding voice to their sometimes existing wireless networks. The result is reduced lines, increa-sed customer service and managers can spend more time on the sales floor (SpectraLink 2005).

5.1.1.9 Transportation and Logistics Transport and Logistics are also industries that can benefit from wireless IP telephony. Such a telephony system can be used to communicate with the staff working at departure halls, airports, train stations etc. It can also be used for communicating with customers who want information about their order or delivery status. In Cisco Systems’ marketing material, they present a case study where a large transportation company had installed a wireless IP telephony solution that was inte-grated with their computer system and covered a large area including 12 buildings. The shipping and recei-ving teams were equipped with Wi-Fi phones that had the same extension number as their office phones. This solution replaced many pagers, mobile phones and walkie-talkies and offered new possibilities.

5.2 Wi‐Fi Phone User Groups A description of these users’ characteristics and con-texts of use is presented in this section, where the actual users are described in more detail.

5.2.1 Different Types of Extensions for Different User Groups According to Mats Höglander (2006), Mobility Mana-ger at Ericsson Enterprise, users are often categorized after their type of mobility. Each group has different communication requirements and limitations. The four most common mobility groups are:

(i) No mobility (ii) Home users (iii) On site mobility (iv) Off site mobility

No mobility includes people who have a desk at work where they spend most of their working day and are

not required to be reached or reach walking away from their desk. A stationary extension is most suitable for this group. Approximately 50 % of the employees at an average company belong to the no mobility category (Ericsson Consumer and Enterprise Lab 2006). This group is outside the scope for this study. Home users include people having a remote office, working from home connecting to the office. Since the-se users are mostly outside the office and its vicinity, Wi-Fi phones are not suitable for them making this group of people irrelevant for this study. On site mobility include people that are mobile on the office premises. This includes receptionists, assistants, administrators, industry workers, janitors and other cat-egories of employees that move around very much in the office building. According to Ericsson’s Consumer and Enterprise Lab (2006), 25 % of all working people are considered to belong to the mobile on site category. This number will probably rise to 34 % in a few years (SpectraLink 2004). DECT phones and Wi-Fi phones are the most suitable extension types for this category, because their mobility makes the stationary extensions unsuitable and mobile phones are a rather expensive al-ternative. Since their mobility is inside the office build-ing, these areas can be covered by installing wireless access nodes throughout the building. The off site mobility group includes people who, in their profession, move around both within the building and to other buildings, cities and countries. Examples of such people are field persons, field service, executives, knowledge workers and consultants. The most suitable extension types for this category of users are mobile phones that work everywhere and IP phones that they can easily hook up to a computer anywhere. As of today’s telephony solutions, Wi-Fi phones are not suitable for this user group because the limited coverage areas. Dual mode phones, using the GSM net-work in addition to Wi-Fi, may be an interesting alter-native for these users.

5.2.1.1 DECT and Wi‐Fi Previous to Wi-Fi, DECT was the only suitable exten-sion type for on site mobility workers (Höglander 2006). Research at Ericsson Enterprise has shown that Wi-Fi phones are suitable for 80-90 % of the DECT users and 30 % non-DECT users, because of the new features and advantages that Wi-Fi telephony offers (Höglander 2006). This big overlap means that most future Wi-Fi phone users will be former DECT users. I will base the rest of my work on this assumption. The type of extension device a specific employer has does not only depend on his or her mobility. It also has


to do with softer issues such as expressing status. The various extension types can be used to differentiate the different levels of employers. For instance, managers may use mobile phones that they can use everywhere while industry workers are to use DECT or Wi-Fi pho-nes that are useless outside the premises. DECT and Wi-Fi phones are therefore interesting alternatives for employers who want to limit the employees’ telephone use outside the office. Since there is no coverage outside the office building, the telephone can only be used at work.

5.2.2 User Group Descriptions As I previously mentioned, the probable users of Wi-Fi phones will be people who are very mobile at work. Examples of such people are industry janitors, hospital personnel and industry workers as well as IT staff at larger enterprises. As I also have mentioned, the predicted users of Wi-Fi phones are to a great extent former DECT users. This section will be based on this finding, describing who the current DECT users are and how they use their phones today and how Wi-Fi phones can be integrated into their communication environment. This section is based on several different sources, and it is important to keep in mind that these generalizati-ons are not true for all users and that different user gro-ups’ telephony use and needs varies greatly depending on location, industry, company etc.

5.2.2.1 Finance Personnel Employees in the finance sector, such as traders and bank customer support, often have a high on premises mobility (Cisco 2003). To be reachable when they are not at their desk, most of them are use wireless phones. The telephone is mostly for basic functions such as calling but sometimes also use PBX functions such as telephone conferencing and parking calls. New features that Wi-Fi telephony will offer in the future, opens up for integrating data and voice transfer to and from a single handheld device. This replaces the need for a PDA, that are common in this industry today (IDC 2003), and a wireless phone.

5.2.2.2 Hospital Personnel Hospital personnel are one of predicted major Wi-Fi telephony users in a couple of years. Nurses as well as doctors are expected to always be accessible during working hours regardless of their location in the hospital. Previous to Wi-Fi telephony, pagers have been used by these groups of users which required plenty of time searching for phones and responding when being paged. Not only does wireless telephony

eliminate this time, it can also offer new possibilities such as alarming and increased information exchange. Apparently, many nurses today carry a wireless phone (mostly DECT) and a pager that receives alarms. Many also carry a PDA that is synchronized with the hos-pital’s computer system and is used for scheduling, e-mailing and accessing common resources (Halvargrud & Sund 2005). In 2001, according to a press release from Intersil (2001), 80 % of the phone calls to a hospital are paged to mobile nurses. The nurses then have to find a phone and call back, which is expensive and takes of time. Wi-Fi phones can improve the communication and co-operation between nurses, doctors and other hospital staff as well as patients (Ascom 2005a). In 2005, Halvargrud and Sund studied how telecommunication is used in Norwegian hospitals. They found that Wi-Fi phones can be used for communicating, accessing in-formation, entering data, monitoring patients, alarming and patient information exchange. Wi-Fi phones can also be used for finding equipment (Ascom 2005a). A telephony system installed in a hospital has certain requirements – the system has to be reliable and robust and offer a high privacy and the handsets have to have a battery that at least lasts throughout a whole shift (Halvargrud & Sund 2005). Most of the common ser-vices such as calling, answering, redial, call-back, parking and transferring calls are used by this user group. Telephone conferencing use in the health care industry is probably limited, though. Other personnel at the hospital, such as repair men, technicians etc are also without a desk and have a need for communication devices (Junthé 2006). These groups of users will be described later in this chapter.

5.2.2.3 IT Staff and Maintenance Engineers IT staff and maintenance engineers, regardless of ind-ustry, often include people assisting employees or per-forming hardware and software maintenance. These people spend much of time away from their desk mov-ing around in the building. Approximately 80 % of the workers in this category are men, and are considered to be early adopters of new technology (Ericsson Con-sumer and Enterprise Lab 2005). Around 50 % of their working time is spent away from their desks, but inside the office building (Sens 2006). Yet, they are people who are expected to be constantly reachable to be able to assist others. This makes wireless telephony a suit-able technology. Not only is this group of users in need of a phone, most of them also use PDA:s and Laptops (Ericsson Consumer and Enterprise Lab 2005). Furthermore, they are often owners of the newest mo-


bile phone and often appreciate services such as doing financial transactions using the handset. Most people included in IT staff are in contact with people both inside and outside the company. They use the telephone for many different things, are early adop-ters of new technologies and features. According to Ericsson’s Consumer and Enterprise Lab, tech emplo-yees use fixed phones as well as mobile phones to a great extent (approx. 70 %). Most of them also have internet and e-mail access in their work. Laptops are used by 38 % of these workers.

5.2.2.4 Janitors Janitors are found in many different sectors, such as hospitals, large enterprises and schools. In their work they are very mobile within the building, making Wi-Fi phones and DECT telephones suitable for them. Most of their calls are internal, but they are also in contact with people outside the company.

5.2.2.5 Managers In Cisco Systems’ sales material, managers regardless of industry are presented as a possible user group, since they often are mobile within the office building spen-ding time in meetings (Cisco Systems 2005). To be more precise, executives spend 33 % of their time in the building but away from their desks (Sens 2006). SpectraLink (2003) break down possible Wi-Fi tele-phony users into two categories; decision-makers and implementers. Managers, who are decision-makers, have to be able to respond quickly and make decisions (SpectraLink 2003). Implementers, on the other hand, spend much time away from their desks doing various things (SpectraLink 2003). According to Ericsson’s Consumer and Enterprise Lab (2006), 81 % of mobile senior mangers and knowledge workers have a fixed phone at work that they use on a regular basis. 82 % use mobile phones regularly at work. Most of these workers have internet and e-mail access at work and a third of them own a laptop (Ericsson Consumer and Enterprise Lab 2006). Most managers use these devices and services for automatic calendar updates, mobile e-mails, etc (Ericsson Consumer and Enterprise Lab, 2005).

5.2.2.6 Blue‐collar Workers Many users of Wi-Fi telephony will probably be work-ing in manufacturing and construction industries, hav-ing mobile jobs. These workers, including the staff in the production lines, move around on the industry floor and benefit greatly from being reachable and accessible. According to Ericsson’s Consumer and Enterprise Lab (2006), blue collar workers have a high degree of

mobility and use few other communication tools in their work. The possibilities with a Wi-Fi telephony solution for these user groups are many. Group alarms, sent out to a number of people, can be used for warning or in-forming of relevant, urgent matters. Wi-Fi telephony also enables communications between colleagues and supervisors, one-on-one as well as conference calls joining several people (Ascom 2005b). Most of the communication in the manufacturing and construction industry is internal, contacting other people in the same building. Beyh and Kagioglou did a study in 2004 where a list of specific telephony needs for construction sites was pre-sented. Firstly, the system should be able to handle transmission of voice, data and video. Access to all project team members was also necessary. Furthermore, the system should be robust, reliable, cost effective and resistant to dust and water (Beyh & Kagioglou 2004). They also suggested that the construction workers should be integrated in the introduction process as early as possible to establish a strong interest among the users. This could be done by having team meetings where a project plan is discussed (Beyh & Kagioglou 2004). The users’ need and the problems with their current system should also be discussed (Beyh & Kagioglou 2004). Beyh and Kagioglou also estab-lished that the technology skills among construction workers were rather low. In industries it is common with impersonal phones; phones that represent a certain professional role (Höglander 2006). The telephone is used during your shift and left for someone else when you leave for the day. Typically, the telephone is the only com-munication device that these people carry around. However, some stock keepers and truck drivers have computers connected to the business system, and are probably interested in being able to communicate with it as well (Höglander 2006). Daniel Fallman has performed a study in 2002 of ser-vice and maintenance personnel at industrial manu-facturing units. The findings were that these workers use several tools apart from their phone and feel that most telephones on the market are developed for the mobile office and not for industry workers. Moreover, the study showed that most of the workers did not search for information in their manuals when they en-countered a problem with their telephone. Instead they either looked at graphical blueprints or they called the telephone manufacturer for guidance. This shows that there is a need for digital blueprints rather than man-uals.


5.2.2.7 Receptionists, Administrators & Assistants Receptionists, administrators and assistants often have a desk with a computer and a stationary phone. But sin-ce they often are required to be reachable at all times, they are often equipped with a wireless phone to be used when they are not located at their desk.

5.2.2.8 Retail Workers & Warehouse Staff Wi-Fi phones are suitable for people working in large stores, such as store clerks, in need of being in contact with the rest of the staff. Most of the people working in retail stores do not have their own desk and spend their working day in different parts of the store, such as the cash register or the inventory. Retail workers are nor-mally only equipped with a wireless phone, such as DECT, mostly used for internal calls. Sometimes they have handheld devices for scanning EAN barcodes in the aisles and check inventory levels. Purchasing staff, however, communicate with people outside the store. They often have a desk and a stationary phone but may want to communicate all the time. According to Ericsson’s Consumer and Enterprise Lab (2006), 57 % of the people working in stores, shops and restaurants use a fixed phone on regular basis. Mo-bile phones are used regularly by 29 % of this group of workers. Only 5 % have their own laptop and fewer than 22 % have regular access to Internet and mail in their work. Furthermore, these workers tend not to see the efficiency potential in using telephony functions such as conference calls, company phone directory, and mobile forms (Ericsson Consumer and Enterprise Lab 2006).

5.2.2.9 Teachers & Other Education Personnel In schools, Wi-Fi phones can be used to improve ad-ministration and give higher communication flexibility for the staff and students. Most of the communication is internal, contacting other people in the school. External calls, to parents for instance, are also made. According to Nortel (2005), teachers can save 14.5 days per year if they are equipped with wireless phones, since this can increase their mobility and productivity.

5.2.3 Wi‐Fi Users’ Telephony Skills and Knowledge Mostly, when users at large enterprises, like those I have presented, receive a new telephone, they are expected to understand how it works. Sometimes they are invited to a short briefing that only 10 % attend; most of the attendants were receptionists, telephone operators and secretaries (Höglander 2006). Quick-guides or manuals are sometimes handed out to the users, together with the telephone (Junthé 2006). Web-based guideline and manual are in some cases available,

but the manuals mostly cover only telephone features and not functions in the PBX. When users encounter a problem, they tackle it in different ways. Some ask the telephone operator for guidance and some avoid using the functions. Many Wi-Fi phones look like DECT phones or mobile pho-nes. This can be rather confusing, since it is not certain that they function in the same way. Generally, most Wi-Fi telephony user groups have no specific knowledge of telephony or technology. Their skills and experience vary significantly, but one can assume that many have previously been in contact with DECT phones or mobile phones in private use.

5.2.4 Most Common Features & Services In a typical PBX there are about 700 available services. A telephone operator normally uses about 40 to 60 ser-vices (Höglander 2006). A typical user uses approxi-mately six services each; with a total of 50 to 60 servi-ces (Höglander 2006). The most commonly used servi-ces, according to Ericsson Enterprise Sales and Marke-ting, are calling, answering, phone number presentation, short numbers, telephone conferencing, call-back and in-call service such as parking and transferring calls (Junthé 2006; Höglander 2006; Berggren 2006). Other common services are support from the call center or telephone operator and directory search in the PBX. Studies from Ericsson’s Consumer and Enterprise Lab (2004) however show that the usage of telephony func-tions is significantly lower. Only three out of 30 res-pondents in a communication survey used features such as speed dialing and speaker phone, and none of them used PBX functions such as voice dialing, auto-matic call forwarding and telephone conference. Other functions such as call transfer and voice mail were however occasionally used by three-four of respondents (Ericsson Consumer and Enterprise Lab 2004). In Israeli and Lund’s article about human-computer interaction in the telecommunications industry, they state that only expert users use telephony functions such as call transfer, telephone conferring and hold. Their belief is coherent to Ericsson’s Consumer and Enterprise Lab, who state that casual end users ignore complex extra functions and only use a few features regularly (Israeli & Lund 2002). They also state that regular users have little opportunity for training and do not read long instructions (Israeli & Lund 2002). In Cisco Systems’ marketing material, the message broadcasting feature is highlighted. It is presented as a feature with great possibilities for informing staff about immediate changes or happenings.

CHAPTER 6. HITACHI USABILITY TEST FINDINGS 23

6. Hitachi WirelessIP5000 Usability Test Findings

In this chapter, the findings from the test session are presented as well as findings from the test preparations. At the beginning of the chapter, findings regarding Hitachi WirelessIP5000 are presented. This section is followed by findings related to the phone’s web interface, followed by the system and PBX related findings and a section about general findings. At the end of the chapter there is a section about the participant’s mental model of the telephony system and how this may have influenced their behavior.

6.1 Findings Regarding Hitachi WirelessIP5000 This section presents the findings from the usability test sessions that have to do with Hitachi WirelessIP5000, its software and hardware. It covers findings from test sessions as well as discoveries from the test preparations.

6.1.1 Starting up the Phone Like most other IP phones, Hitachi WirelessIP5000 has a password and user ID when initiating contact with the PBX. In contrast to other IP phones, however, this is not entered when starting up the phone. Instead, this information is stored in the telephone, and therefore it only has to be entered once, preferably by the telephone administrator. This has its pros and cons. One of the benefits is that it is easier for the user to log on to the system. This, however, results in lacking se-curity, since anyone can take a phone and start using it. Another drawback is that the free seating feature can not be used. If one would want to logon to another ex-tension with same phone number that is used in a Wi-Fi phone, this will be possible. But since the Wi-Fi phone constantly tries to reconnect itself to the PBX, the free seating feature only works for a short while, until the Wi-Fi phones automatically reconnects to the PBX with the same phone number. This makes the other extension, which you chose to log onto, go offline. In the telephone configurations, the reconnec-tion interval can be set between 60 and 86400 seconds. If this time is set to a maximum, the user can be placed

at the new extension/”seat” for 24 hours without being logged out. But having such a long reconnection inter-val can cause problems. The Wi-Fi phone will for instance not reconnect quickly after an interruption in the PBX or access point.

6.1.1.1 Free Seating Incompatibility The free seating feature offered by MX-ONE is, because of the issues listed above, to consider incomp-atible with Hitachi WirelessIP5000.

6.1.1.2 Problems Finding the On/off Button It was not obvious for the test participants that the end button (used for hanging up calls) also is the on/off button. This was not indicated on the phone. Initially, most of the participants looked on all sides of the pho-ne, trying to find a specific on/off-button. Everyone eventually tried the end button, though, most of them referring to Ericsson’s former mobile phones that wor-ked similarly. When turning off the phone, most of the participants tested the end button directly. Some pres-sed the button for a too short period of time. They therefore tried to find another “correct” button, before they pressed the end button again and succeeded. Even though this button may be difficult to find the first time, it has a high memorability, and probably no one would encounter any problems if they were to use the phone again.

6.1.2 Navigation Most of the participants had no problems navigating through the phone’s menu. For instance there was no


difficulty in finding where new numbers were added in the phonebook. This is probably because Hitachi WirelessIP5000’s user interface is similar to many DECT interfaces and old mobile phones in terms of the menu structure and functionality.

6.1.2.1 Scrolling Problems The scrolling function, for instance found in the phone book, caused confusion and problems for four of the 11 test participants. When the participants were to add a new contact to the phone book, they could only see two fields in the display; name and nickname. To be able to fill in the phone number field they had to scroll down. The users that did not notice this tried to save the entry without having filled in the phone number. This gene-rated an error message that the participants could not interpret, so they used another method. They went back to the beginning, entered the phone number, and then pressed options – save, instead of calling the number. They could then fill in the name and nickname fields.

6.1.2.2 Problems Finding & Using the Clear Button There were a few buttons that the test participants had problems with or did not understand or use. I will now present the problems associated with the clear button. The clear button erased one character or went back one step in the menu. Half of the participants never found this button or never started using it, and therefore they erased everything each time they wanted to erase one character or went back to beginning instead of only a step. Several participants started using the clear button after while, though. This button has a rather high mem-orability, so most of the users would probably remem-ber how to use it once they found it.

6.1.2.3 Problems Finding the Enter Button The enter button, found in the middle of the joystick, was also tricky to find. Everyone found it after a while though, since it was essential to be able to use the phone.

6.1.3 Unclear & Incoherent Terminology The terminology caused problems for the participants, because they did not understand the meaning of speci-fic words or because the terminology was incoherent. For instance, several participants were confused by words such as index, group, web interface etc. The terminology was incoherent in several places, where for instance the manual and the phone used two different words for the same thing. The terminology in-coherence caused confusion in one of the tasks in the test session; in the phone’s phone book, there was a field called nickname. In the web interface, the same

field was labelled read name. This caused confusion for a few of the participants.

6.1.4 Incompatible Features found in the Phone There are several features found in the phone that are not compatible with the MX-ONE telephony system, and therefore can not be used. Examples of this are the presence feature and the possibility to send messages. This may cause confusions for the users since these functions are found in the Wi-Fi phone’s menu. It is however possible to inactivate these telephone func-tions via the web configuration page, which makes them disappear from the telephone’s menu. I strongly suggest that this should be done by the telephone administrator, since this decreases the risk of confusion for the users.

6.1.5 Limitations in the Phone When exploring Hitachi WirelessIP5000, I came across several limitations in the phone. It is, for instance, not possible to access the menu or phone book during a call. As a result, if the user wants to forward a call, he/she has to know the receiving number by heart. This limitation is due to the phone, and can therefore not be changed by Ericsson.

6.1.6 Unused Functions There were a few features that none or very few of the participants used during the test sessions. This is prob-ably because they had not found the feature and that they used the phone for a very limited time. An exam-ple of this is the call list, which was only used by one test participant. The call list could easily be reached by pressing the joy stick to the left (for received calls) or to the right (for dialed numbers). The call list was also found in the phone’s menu.

6.1.7 Use of Manuals All participants used the manuals at least for one task assignment in the test. It was however clear that most of the users did not know where to find information. For instance, several users searched for guidance using the PBX functions or the phone’s IP address in the phone’s manual. For most of the users it was also un-clear when to use the web management manual. Most of the participants requested that more help should be given online. For instance FAQ:s, quick gui-des and a help search function was requested, to be available on the Internet.


6.2 Findings Regarding the Web Interface In this section the findings that specifically are related to the web interface are presented.

6.2.1 General Uncertainty Most test participants did not understand what a web interface is and how it can be accessed. Most parti-cipants searched through the manuals, but still did not realize what to do. It was unclear that a computer was to be used, even though this was mentioned as a part of the task assignment. When instructed to use the com-puter, it was unclear that the web browser was to be used. Several participants searched through the com-puter looking for special software for handling the phone. Most of the participants eventually figured out that the web browser was to be used. At this stage, it was unclear what web address to enter. After reading the manual, most of them realised that it should be the host followed by port number. Even-tually almost all participants understood that host meant the IP address of the phone.

6.2.2 Problems Finding the IP Address Most of the test participants tried to find the phone’s IP address in the manuals. Some of them used the exact IP address as given as an example in the manual. Others looked in the quick guide and on the sheet with tele-phone numbers. Most of the participants were in-structed that the IP address was dynamically assigned and were to be found in the phone. All the participants then thought that they could find the IP address in the network submenu. Eventually all participants looked in the correct submenu located under setup\information\TCP/IP.

6.2.3 Difficulties entering the IP Address Having found the IP address, the participants tried entering it in the address field in the browser. Two out of six entered it correctly. The other four entered the IP address and the port number with brackets <> around them. This was due to the text manual where the add-ress was presented as http://<host>:<port> . After in-structions were given the brackets were removed and all participants managed to log in.

6.2.4 Easy Using the Web Interface When having logged in, the participants had no problems entering a new number in the phone book. About a half of the participants entered the external phone number without the external prefix (00).

Even though all participants had difficulties entering the web interface, most of them had a positive attitude towards it. Most of them mentioned that they probably would use the web interface if they were to enter several new numbers in the phone book.

6.3 System Related Findings Pre-test and test findings regarding the PBX and its interaction with the phone are presented in this section. This includes making calls, the use of PBX functions, etc.

6.3.1 Making Calls There were no problems making internal calls. The participants knew what to dial and had no problems with starting and ending a call.

6.3.2 Caller ID & Call List Issues When calling to the Wi-Fi phone, the caller’s telephone number is not shown in the display. If it is an internal call, the caller’s SIP URL is shown. This SIP URL is also shown in the call list after the call. This generates problems, since the user can not call back to this number via the call list. If it is an external call, “no caller ID” is shown in the display. When entering the call list after the call, “pu-blic” is shown instead of the actual telephone number. As a result of these issues, the received calls list can not be used for making calls.

6.3.3 Uncertainty about the External Prefix Several participants, especially the non PBX-experien-ced users, first did not enter the external prefix (00) when making an external call. Since this did not work, most of the participants realised that 00 needed to be added before the number. One participant, who was aware of the need of the external prefix, did not know when to use it. He was uncertain of what was internal respectively external nu-mbers. For instance he did not know whether the voice box number was internal or external. As I mentioned earlier, 3 out of 6 participants forgot to enter the ex-ternal prefix before the phone number when entering a new number in the phone book via the web interface.

6.3.4 Voice Mail A few participants did not know how to reach the voicemail. Some looked in the phone’s manuals for


guidance; others search through the phone’s menu, looking through the call list etc. Most of the participants, however, found the number on the information sheet and were able to quickly access their voice mail. One participant, after listening to the messages, pressed * to quit, as prompted in the voice instructions. This however took the user to the main “Welcome to the Ericsson Voice Mail System” which made the test participant very confused. Except for this issue, the voice mail function was easily used for most of the participants. A few problems and confusion occurred though. Some of the participants looked through the phone’s menu, trying to find the voice mail.

6.3.5 Lack of Confirmation and Feedback All participants experienced a lack of confirmation when using PBX functions such as call back and absence. When having entered the right codes (found in the quick guide), and hung up as they were supposed to, none of the participants knew that they were done and had entered the command correctly. This was due to the confusing or unfamiliar tone message(s) heard after entering a command. Another finding was that few participants actually knew that they had managed to finish the task. Instead they thought that there was something missing and that they had to enter the command again. This had to do with two things; first of all there is a lack of feedback and secondly there is a lack of confirmation. For insta-nce, when having entered the absence code three short beeps are heard. None of the participants realized that this was a confirmation. Few knew if they could hang up or not. These beeps are also heard when having entered an incorrect command, such as meeting until 48 o’clock. The participants that entered the wrong time did not realize this. The same goes for the call back function, where the participants did not know if they had activated it or not, when they had pressed 5.

6.3.6 Lack of Status Awareness Several participants requested a possibility to see which status the phone/extension currently has, such as if the lunch absence or call-back functions are activated. Several test participants requested this information to be shown in the display. The phone has a built in Presence function that can show whether you are online or offline or not at your seat to other users. But this feature was deactivated by system administrator as not to interfere with or confuse the users, when the

phone is connected to a PBX system implementing a different presence concept.

6.3.7 Quick Guide All test participants used the quick guide for guidance when performing the test assignments involving PBX functions, such as call back and absence code. Almost all participants were annoyed that the informa-tion and guidance was found in several different places. Most of the participants requested the functions to be added to the phone’s menu or numbers to be found in a special folder in the phone’s phone book. To be able to benefit from this the phone software must be rede-signed to allow phone book access when in call state. The user experience would also be improved by this as a user would be able to browse the phone book for data when talking.

6.4 Rated Findings Summary In this section I present the general findings from the usability tests on Hitachi WirelessIP5000. This sum-marizes the most important parts of what has been presented earlier.

6.4.1 Lack of Confirmation and Feedback The usability tests on Hitachi WirelessIP5000 made it clear that the feedback given to the users is not sufficient. As mentioned in section 4.2.1.4 a lack of feedback is a general problem in most phones today. Feedback is however very important, and is one of the heuristic usability principles. There is a need for more and clearer feedback and con-firmation. As I mentioned earlier, several participants were not aware that they had finished a task, such as entering absence, just because they did not get any clear feedback

6.4.2 Lack of Status Awareness Many participants reacted on the fact that they did not know if they had the absence code activated or not, and whether the call back function was actually activated. This illustrates the need of increased status awareness.

6.4.3 Uncertainty of where to Find Guidance All participants used the manuals for at least one task assignment in the test. It was however clear that most of the users did not know where to find guidance when they needed it. For instance, several users searched for guidance using the PBX functions or the phone’s IP address in the phone’s manual. For most of the users it


was also unclear when to use the web management manual. Most of the participants requested that more help should be given online. For instance FAQ:s, quick guides and a help search function was requested, to be found online.

6.4.4 PBX Codes are Confusing One of the first findings in this Master’s project was the difficulty of activating functions in the PBX using a Wi-Fi phone or any other type of extension that does not use a menu system for telephony functions. In the Wi-Fi phone, the call waiting function, for instance, is activated by dialing 5 and the absence function uses the code *23*. This is not obvious to the users and it also lacks natural mapping. The reason why the functions are activated using these codes is that the SIP protocol, which is used in the communication between the phone and the PBX, can only communicate using numbers (0-9) and * and #. The usability tests verified this issue. All participants mentioned that they would not be able to activate all the functions if it was not for the quick guide with all the PBX codes. Even though they had this quick guide, many of the participants were annoyed by the fact that they had to use codes to activate these functions. Several also dialed the wrong number combination, etc. They all thought that the absence message for instance should be entered in a different way, such as in the phone’s menu. If this is not possible, several participants mentioned that they would like these codes to be found in a special folder in the phonebook. In usability theory complicated functions can be measured by two parameters:

(i) Memorability (ii) Frequency of use.

Tricky functions with low Memorability are functions that are tricky even though you may have used it several times because it is difficult to remember how to use it. An example of this is the absence codes used in MX-ONE. Even though you may have activated it seven times it can still be very tricky to remember the combination *23*3*1730#. Tricky functions with a high memorability factor are functions that are tricky to figure out for the first time. But if you have done it once, you will remember how to do it again. An example of this type was the on/off button on the Hitachi Wi-Fi phone. Some had problems finding at first, but probably everyone would remember that it was the end button, the next time they wanted to turn on or off the phone.

The other relevant parameter is Frequency of use. A function that is used several times a day will soon be memorized by the user almost no matter of how tricky it is to activate. Functions that are needed seldom and are tricky to activate, with a low Memorability, will however probably not be used.

6.4.5 Need of Improved Guidance regarding the Web Interface First it would be preferable if the user manual and web configuration manual could be joined. The test participants were annoyed that the information was found in several different places and that these functions could not be activated in a easier way. Almost all participants requested these functions to be added in the phones menu or numbers to be found in a special folder in the phone’s phone book. To be able to benefit from this the phone software must be redesigned to allow phone book access when in call state. (The user experience would also benefit from this as a user would be able to browse the phone

6.5 Mental Model As I mentioned in section 4.2.4, the mental model refe-rs to the way the users look upon the Wi-Fi phone and the rest of the telephony system. One of the goals of the usability tests was to establish what the participants’ mental models of the Wi-Fi tele-phony system looked like. This was established by examining how they tackled problems, where they looked for guidance and also what they answered in questionnaire after the tests, where several questions were to reflect the mental model. It was clear that the participants with experience from configuring wireless networks at home for instance, us-ing IP numbers etc had an advantage when entering the phone’s web interface. They had a greater under-standing of how the telephone can be accessed from a computer. None of the test participants knew where to find the phone’s IP address. Many looked for the IP address in the phone’s manual, which gives an insight into the test participants’ mental models; they believed that the IP address was fixed and was preprogrammed by the phone manufacturer. It was however obvious, that the test participants with greater experience in using PBX phones had a greater understanding of when and where to use the external prefix and not, and which phone numbers were internal contra external. These test participants therefore had no problems making internal calls or knowing whether


the external prefix was to be used for the voice mail service. Apart from these two matters, the mental model did not seem to influence the users’ behavior. After the tests some users, experienced and inexperienced, where a bit confused by the web interface. It was clear that they did not completely know what they actually had done when they entered

the phone’s web interface. One test participant, currently using a DECT phone, for instance thought that her current DECT phone also had a web interface. This fact, proves my theory that most of the future Wi-Fi phone users will not be aware of the difference between this phone and a DECT phone since the user interfaces are similar and the function similarly.

CHAPTER 7. COMPARISON WITH ASCOM i75 AND ACCTON VM1188T 29

7. Comparison with Ascom i75 & Accton VM1188T

In this chapter the usability comparison between Hitachi WirelessIP5000, Ascom i75 and Accton VM1188T is presented. The chapter begins with an explanation of how the Wi‐Fi phones were compared, and which parameters that were evaluated. Summarizing tables for the comparison are found at the end of the chapter.

7.1 Comparative Usability Evaluation When comparing Hitachi WirelessIP5000 with Ascom i75 and Accton VM1188T, I chose to base my evaluation on the heuristic principles (see section 4.1.3) combined with the usability goals presented in section 4.1.2. I however chose not to include all the parameters. Instead, I chose only the parameters and issues that showed to be relevant in the usability tests conducted on Hitachi WirelessIP5000. For instance, since users were not involved in the evaluation, user experience goals such as enjoyable, entertaining and motivating are difficult to estimate and will therefore not be part of the usability comparison. The chosen parameters are presented below:

(i) Speaking the user’s language (ii) Minimizing the user’s memory load (iii) Consistency (iv) Feedback & Status awareness (v) Learnability (vi) Memorability (vii) Efficiency & Shortcuts (viii) Errors (ix) Help and documentation (x) Subjective satisfaction

In the following sections, all these parameters are presented in more detail with an explanation of why these parameters were used for the usability comparison between the three Wi-Fi phones. I will also present how well each Wi-Fi phone meets these criteria.

7.1.1 Speaking the Users’ Language Speaking the users’ language is one of Jacob Nielsen’s heuristics rules (Nielsen 1993). In order for the inter-

action between a user and product or system to be successful, it is very important to use words and con-cepts that the end users are familiar with. It is also es-sential that the meanings of the words that are used in the interface map the users’ meanings of the word.

7.1.1.1 Hitachi WirelessIP5000 As I previously described, the usability tests on Hitachi WirelessIP5000 showed that most of the users are not familiar with words such as index, group and web interface, which resulted in that they avoided these words or had problems using them. Japanese and English are the two available languages.

7.1.1.2 Ascom i75 It is evident that the words used in Ascom i75 are easier to understand than the words in Hitachi WirelessIP5000. This is however also linked to the fact that Ascom i75 does not have as much functionality as Hitachi WirelessIP5000. There are for instance no contact groups in the phone book that may cause confusion for the users. Moreover, the user can choose between several differ-ent languages, such as English, Swedish, German, Norwegian etc.

7.1.1.3 Accton VM1188T The terminology used in Accton VM1188T consists mainly of very common and easy words that most users will probably understand. It is mostly words that the users will recognize from their mobile phones. For instance Accton VM1188T supports several “ringing profiles”, which Hitachi unconventionally names “Bell/Vib”. Furthermore, more information is mostly


presented than in Hitachi’s Wi-Fi phone. For instance, when having dialed a number, there is an option to “save to contacts” instead of only “save”. Unfortunately, English is the only available language.

7.1.2 Minimizing the Users’ Memory Load Minimizing the users’ memory load is another heuristic rule that basically means that the user’s memory should not be loaded with unnecessary information. For instance, the user should not be required to memorize information to be used later in the interaction.

7.1.2.1 Hitachi WirelessIP5000 Hitachi WirelessIP5000 is preconfigured by the telephone administrator when the users receive their phone. In contrast to many other enterprise wireless phones, Hitachi WirelessIP5000 is preconfigured with a certain telephone number and password. As a result, the user does not log on manually to the phone to be able to use it; this is done automatically. The user therefore does not have to memorize his or her phone number. This automatic logon, however ties a user to a specific phone. When using Hitachi’s Wi-Fi phone it is not possible to access the phone book during an active call. This means that the users have to memorize phone numbers to be able to transfer calls. There is an option to press the start call button, which puts the active call on hold, but this is a phone feature, which is not compatible with the transfer and conference call features that will be available in the PBX.

7.1.2.2 Ascom i75 Since I could not fully use Ascomi75, because of the configuration difficulties, not all features could be eva-luated. It is however clear that Ascom i75 has several features that minimize the users’ memory load. For instance, the phone is not locked during calls. The users can therefore perform operations during an active call, such as look up or store a number.

7.1.2.3 Accton VM1188T In contrast to Hitachi WirelessIP5000, the phonebook in Accton VM1188T is accessible during calls. The user therefore does not have to memorize any phone numbers in order to transfer a call or look up a number during a call. The user does not have to memorize his or her phone number, since this is stored in the phone. Once you have started the phone it automatically logs on. This however ties a user to a specific phone, as with Hitachi WirelessIP5000.

7.1.3 Consistency Consistency is a major usability principle meaning the similar things should be presented in a similar way. For instance, the procedure to save an entry should be consistent through out the user interface. Consistency also covers terminology, graphical objects etc.

7.1.3.1 Hitachi WirelessIP5000 There was an obvious lack of consistency found in Hitachi WirelessIP5000, concerning the terminology as well as the interaction. For instance the scroll function found in the phonebook caused problems since it was not found elsewhere in the phone. Another issue in Hitachi WirelessIP5000 was the on/off button, which was the hang up button. This is consistent to Ericsson’s old mobile phones, but it was not indicated on the phone and therefore caused confusion. The terminology in the phone is not the same as in the manual and the web interface, which caused confusion a couple of times during the usability tests.

7.1.3.2 Ascom i75 Ascom i75 is consistent in several ways. The phone reuses old design and interface conventions. For instance, Ascom i75 is very similar to Ascom’s DECT phones, both in terms of the exterior and software. The terminology and other parts of the interface are also to be considered consistent.

7.1.3.3 Accton VM1188T Accton VM1188T resembles many of the characteris-tics and interface of most mobile phones. One thing that is not very consistent to mobile phones is how to access the menu. On Accton VM1188T the menu is accessed by pressing in the middle of the joystick, which is not clearly indicated.

7.1.4 Feedback & Status Awareness Feedback has proven to be very important for the interaction between the user and the Wi-Fi phones to be successful (see section 6.3.5). Feedback is also one of Nielsen’s heuristic principles, which states that it is essential that a telephony system or a phone keeps the user informed of what is going on. This principle is linked to the status awareness principle, presented in section 6.3.6. Nielsen (1993) refers to this principle as visibility of system awareness. Status awareness has to do with letting the users know what is going on. This is done by providing sufficient feedback. Most of the feedback and status awareness issues found in the usability tests were not specifically related to the


phone. Instead, it had to do with using PBX functions, and not getting any information back from the PBX. In the following sections, the phone specific findings that have to do with feedback and status awareness are presented.

7.1.4.1 Hitachi WirelessIP5000 During the usability tests it was evident that that not all feedback from the phone was correctly interpreted by the test participants. For instance, when the users were not aware of the scrolling feature in the phone book, the error message in the phone did not guide them onto the correct track.

7.1.4.2 Ascom i75 There were no apparent lacks of feedback and status awareness that specifically had to do with Ascom i75. The lack of feedback and status awareness that affected the use of Ascom i75 had to do with the PBX.

7.1.4.3 Accton VM1188T Accton VM1188T often has a rather long response time, which is why the phone appears to be very slow. When the system or phone fails, which it did rather often during the tests partly due to lacking coverage, no comprehensible feedback is given.

7.1.5 Learnability Learnability is about learning to use a new system such as how long it takes to learn the system and the necessary knowledge level. The quicker a user can start using the system, the better the learnability. Examples of learnability measurements are frequency of error messages, frequency of support etc.

7.1.5.1 Hitachi WirelessIP5000 The learnability was lacking in Hitachi WirelessIP5000 partly because there were several buttons that caused problems or were not used by most of the participants. Examples of such buttons are the on/off button and the save/enter button. The usability tests showed that the clear button, indicated with CLR, was not understand-able for several test participants. Neither was the call list, accessed by pressing the joystick to the right or left.

7.1.5.2 Ascom i75 All the buttons on Ascom i75 are clearly indicated, increasing the learnability parameter. The call list function, accessed by pressing the down button was however not indicated.

7.1.5.3 Accton VM1188T The on/off button was not indicated on the phone, but it was the same button as on Hitachi WirelessIP5000 (the hang-up button). The call list was accessed by pressing the start call button. This was not indicated but was similar to many other wireless phones. Another learnability issue is that it was not apparent how to save an entry. For instance, when having filled in the information for a new contact in the phone book, it was not obvious what to press to save the contact. The entry was saved by pressing back.

7.1.6 Memorability Memorability has to do with how easy it is to use a product or system, when the user, who once has learned to use the system, returns after a period of time. Since the Wi-Fi phones that are analyzed in this report, probably will be used on a regular basis, the memorability in using the actual phone is not of great importance. The memorability is therefore considered to be the same for all of the Wi-Fi phones. Memorability does however play an important role for PBX functions that are used infrequently. I believe that the PBX codes’ low memorability is one of the major reasons why they are not used to a greater extent. The users need reminders, clues and assistance in the interaction or the phone’s interface to be able to remember how to perform certain tasks. This is further discussed in the next chapter.

7.1.7 Efficiency & Shortcuts The system or product should support a high level of productivity. For a product or system to work well for novice users as well as experienced users or expert users, it is recommended to use shortcuts or accelerators. These shortcuts should be invisible to the novice users but make the experienced user’s interaction more efficient.

7.1.7.1 Hitachi WirelessIP5000 Hitachi WirelessIP5000’s call list can increase the efficiency in using the phone. The shortest way of accessing the call lists (pressing the joystick to the right/left) was however not indicated. The call list is also accessible from the main menu. The call list was used to a small extent during the tests, which may have to do with the insufficient indication. Hitachi WirelessIP5000 supports speed dial that can be customized in the phone book.


7.1.7.2 Ascom i75 Ascom has 3 soft keys, where two of them can be used as shortcuts to any features or functions in the phone or be used as speed dial buttons. The user can customize these buttons in the handsets menu. In Ascom i75’s main menu there is a feature called services, where the user can program his or her own services. Each service can be freely named and can be linked to a phone number, a prefix, a message address, or data. This means that PBX codes for functions such as the absence function can be stored here. The users can configure their own shortcuts, speed dials and services, increasing the efficiency. The call list in Ascom i75 is accessed by pressing the down button, which is not indicated on the phone. The phone also includes other shortcuts, such as saving numbers from the call list.

7.1.7.3 Accton VM1188T The call list is easily accessed from the start call button. The call list is very similar to the call list found in most Sony Ericsson mobile phones today, where the missed and dialed numbers can be separated from the received. When entering a phone number the phone suggests different numbers based on what you have started to dial. These numbers are from the call list or phone book. As in Hitachi WirelessIP5000 and Ascom i75, it is possible to dial a number and then choose to save it in the phone book. Numbers can also be saved from the call list. The phone supports speed dial.

7.1.8 Errors It is recommended that a usable product or system tries to prevent errors from taking place. It is also essential that the number of possible errors is limited and that the results of an error are non-catastrophic.

7.1.8.1 Hitachi WirelessIP5000 The option to disable features like presence, so that they are not visible in the phone prevents the user from trying to use these non-working features.

7.1.8.2 Ascom i75 When exiting the coverage area, and trying to make a call, the system fails and the phone has to be rebooted. Sometimes the battery has to be ejected in order to complete the reboot. In Ascom i75, the user can decide what should be shown in the display. For instance the user’s name can

be displayed. This can prevent users from mixing up their phones. The risk of mixing up phones can be fairly large if the staff’s phones are identical and have to be charged fairly often. This feature reduces this risk.

7.1.8.3 Accton VM1188T When exiting the coverage area, and trying to make a call, the system fails and the phone has to be rebooted. The on/off button is not available then, why the phone’s battery has to be ejected in order to be able to reboot the phone. Like Hitachi WirelessIP5000, Accton VM1188T can put a call on hold and transfer between two calls. When using these functions, the phone’s system fails and has to be rebooted by removing the battery. Furthermore, this feature is not compatible with the transfer and con-ferencing feature that will be available in the PBX.

7.1.9 Help & Documentation Help and documentation are often necessary. To in-crease the usability, the guidance should be easy to find, be focused on the task that the user wants guidance with and list concrete steps of how to solve the prob-lem for instance. It is also essential that there is not too much documentation.

7.1.9.1 Hitachi WirelessIP5000 Hitachi WirelessIP5000 is delivered with a user manual, a web configuration manual and a manual for the telephone administrator. During the usability tests it was clear that most of the participants did not know where to find help. Un-fortunately this issue remains with the Ascom i75 and Accton VM1188T since these phones’ manuals only cover the phones. Apart from this documentation, it is clear that the users need access to a quick guide with the PBX codes if they are expected to be able to use these features. During the tests it was also clear that Hitachi’s Wi-Fi phone’s manual did not give sufficient help when describing features such as the web interface.

7.1.9.2 Ascom i75 Ascom i75 is delivered with a pocket-sized quick reference guide and a complete user manual. If the user needs help with settings, the telephone administrator can not configure the phone remotely, since there is no web interface.

7.1.9.3 Accton VM1188T Accton VM1188T that was used in the usability evaluation did not come with a manual. Neither did I find a manual on Accton’s web page.


7.1.10 Subjective Satisfaction It is essential that the users find the system or product pleasant to use. Whether a product or functions is used or not, is the result of the users’ subjective satisfaction. Higher satisfaction results in a higher usage which in turn generates a larger business value (Israelski & Lund, 2002). Normally, the satisfaction is estimated with help from questionnaires and other feedback from the actual users. In this study, there have only been questionnaires about Hitachi WirelessIP5000. The topics presented in this section are therefore things that are likely to influence the users’ subjective satisfaction.

7.1.10.1 Hitachi WirelessIP5000 Hitachi WirelessIP5000 is a robust phone that during the tests and evaluations has been fully functional. This should increase the subjective satisfaction.

7.1.10.2 Ascom i75 Ascom i75 is a very configurable, where the expert or experienced users can change many different kinds of settings and adapt the phone to their use context. For instance, Ascom i75 has several user profiles, programmable buttons and functions. This is likely to increase the subjective satisfaction for these users. It is

however unclear how the inexperienced phone users would consider Ascom i75. The fact that Ascom i75 handles many different lang-uages should however increase the subjective satis-faction.

7.1.10.3 Accton VM1188T Accton VM1188T is more modish than Hitachi WirelessIP5000 and Ascom i75. This may appeal certain users. In the study by Cadiz et al.(2004), the users preferred telephones with screens rather than standard phones. For the same reason Accton VM1188T’s color screen might increase the subjective satisfaction. Accton VM1188T does however not respond quickly to input and commands, which is why it appears to be very slow. It also freezes sometimes, and can not be turned off then. At this point, the battery has to be removed in order for the phone to reload. Accton VM1188T is very slow when starting up. It takes more than a minute for it to load all the infor-mation and connect to the network. This probably decreases the subjective satisfaction among the users.


7.2 Summarizing Table Table 1 (found below) summarizes relevant and comparable data about the three Wi-Fi phones. When evaluating parameters such as speed, comparative measures between these three phones have been taken. Table 1. Summarizing Table Feature/function Hitachi WirelessIP5000 Ascom i75 Accton VM1188T

Size Small Bigger Small

Weight 101 g 145 g n/a

Display Black/white Black/white, immersed (thereby protected from scratches) Color

Max call time 3 hours 10 minutes 6 hours 3 hours

Max standby time 55 hours 60 hours 50 hours

On/off button Hang up button; not indicated Hang up button; indicated Hang up button; not indicated

Menu button Left Soft key; indicated Left Soft key, indicated Middle of joystick (soft key); indicated with an M

Buttons Rather small Separated; easy to press Small; difficult to press

Menu system/Interface Text based.

Graphical and text-based. Main menu consists of icons. The rest is text.

Graphical; similar to many mobile phones.

Start up Logs on automatically; user information stored in phone. Quick. Virtual sim or automatic log on

Logs on automatically; user information stored in phone. Slow startup; takes more than 1 minute to load settings.

Call list Accessed by pressing the joystick to the right or left; not indicated. Also found in menu. Stores the X last calls.

Accessed by pressing down. Stores 20 last calls.

Accessed by pressing the start call button; not indicated. Also found in menu. Stores the X last calls.

Phone book – enter information

Rather difficult; Scrolling function unclear. Slow speed.

Simple; two fields to fill in. No scrolling.

Rather simple; Scrolling function rather clear

Phone book – save entry Difficult; press enter button; not indicated. Simple; press save button Difficult; press back; not indicated.

Speed Fast Fast Rather slow

Terminology Rather simple. A few tricky words. Simple; especially because of several languages Simple.

Call back Available Could not be tested. Not available; system fails and has to be rebooted by removing battery.

Absence code Available Could not be tested. Not available; system fails & needs to be rebooted by removing battery.

Remote configuration/Web interface

Available in a user and an administrator mode. Enables remote configuration.

Ascom i75 can be remotely configured by the telephone administrator via the PDM software. Could not be tested.

Remote configuration available, but could not be tested.

Manual Phone manual, administrator manual, web configuration manual

User manual, pocket size manual, administrator manuals No manuals

Other Pros - Reliable

- Robust & Reliable

- name in display

- shortcuts

- central phonebook

Other Cons - system fails frequently

CHAPTER 8. RESULTS ANALYSIS AND PROPOSALS 35

8. Results Analysis & Proposals The results from the usability tests were used to establish how the usability of using PBX features and service via a Wi‐Fi phone can be increased. The improvement proposals are presented in this chapter.

8.1 Results Analysis One of the major findings in my Master’s project is that the end users do not use the PBX functions very much. I believe that this has to do with several parameters;

(i) Awareness: The users have to be aware of the functions

(ii) Benefit: The users have to benefit from using the functions

(iii) Easy to use: The functions have to be easier to use and activate

The first parameter, regarding awareness, is very essential. If a user is not aware of the functions he or she will not even try to use them. The users can possibly become aware of the PBX features from the telephone administrator or from information in the phone or manual. Colleagues or the Internet can also inform the users. This factor lies outside the scope of my Master’s project and will therefore not be further discussed. The second parameter, regarding the benefits the user receives from using the function is also essential. When discussing PBX codes, a user may think it is easier to call a person again instead of figuring out how the call-back function is activated. It may also be easier to return missed calls, due to a meeting, rather than activate the absence codes. Most of the expected users, such as nurses, janitors and manufacturing workers do not have their own desk. Do they benefit from a web interface, when updating the contacts in their phone book? Automatic synchronization may be more interesting for these target groups. Since this parameter does not have to do with usability, it is excluded from my Master’s project . The third parameter, easy to use, has to do with usa-bility and is therefore covered in this Master’s project . By increasing the usability, it is easier for the user to use the phone and the PBX functions which maximizes

the possibility that the users actually use them. As mentioned earlier in this report, usability has to do with several different parameters, such as efficiency, satisfaction and effectiveness.

8.1.1 DECT Phones contra Wi‐Fi Phones As mentioned earlier, several test participants did not notice or understand the difference between DECT phones and Wi-Fi phones. The usability tests also showed that a mental model based on this conception, did not affect the test results. The participants that believed that there was no difference between the Wi-Fi phone used in the test and their DECT phone, did as well in the test assignments as the other participants, except for in the web interface assignment. There is therefore no need to inform the users of this difference. The benefits of and differences with Wi-Fi telephony mostly affects the telephone administrators and the expenses, since Wi-Fi telephony can be a more cost effective solution.

8.1.2 Outline of this Chapter In the upcoming sections, I have chosen to present proposals that in different ways can increase the usability in using a Wi-Fi phone connected to MX-ONE. Some of the proposals are phone specific; others have to do with the interaction with the PBX. Several proposals have to do with the same issue, and are therefore grouped together.


8.2 Conclusions from the Phone Comparison When comparing the three Wi-Fi phones, it was obvious that they were adapted to and more suitable for different groups of users. Figure 5 summarizes this section.

8.2.1 Ascom i75 Ascom i75 is most suitable for blue collar workers, nurses, janitors and other personnel working in rough environments. This has partly to do with the phone’s size and material. It is more robust than the other two Wi-Fi phones and the display, for instance, is a bit immersed, to protect it from scratches. The phone is also equipped with a hinge type clip on the back, which makes it easy to clip onto a belt and carry around. Ascom i75 has a virtual SIM-card solution, where a user can take any phone and log in with his or her phone number.

8.2.2 Hitachi WirelessIP5000 & Accton VM1188T Hitachi WirelessIP5000 and Accton VM1188T both feel more adapted to managers, IT staff and assistants. These phones are significantly smaller than Ascom i75, with smaller buttons and have a design that is similar to mobile phones’.

Since Hitachi WirelessIP5000 and Accton VM1188T are suitable for different users than Ascom i75, it is more relevant to compare Hitachi WirelessIP5000 to Accton VM1188T. One comparing these two phones, it was obvious that Hitachi WirelessIP5000 was a bit more robust and quicker to respond, meanwhile Accton VM1188T had a color display and used a terminology that was easier to interpret. Both phones had a usability that was significantly lower than Ascom i75. I would consider Hitachi WirelessIP5000 to have a slightly higher usability than Accton VM1188T, mainly because the phone has a user manual, is quicker and does not have as many system failures. For some users, Accton VM1188T would generate a higher user satisfaction because of its design and color display, but for the majority of the business users, Hitachi WirelessIP5000 would generate a higher user satisfaction in the long run.

8.3 Functionality of Interest for the Users Since the predicted users of Wi-Fi telephony are people on the move inside a building, doing many things at the same time as making calls, it is important to minimize the required interaction and attention needed with the phone.

Retail workers and warehouse staff

Figure 5. An overview of the suitable user groups for the different Wi-Fi phones. Information from the user profiles and Ericsson Consumer and Enterprise Lab.

0


One also has to consider the PBX functions that might be of interest to the Wi-Fi users. My user categoriza-tion studies show that most of the predicted Wi-Fi users work at hospitals and industries, etc, where the Wi-Fi phone is probably their only phone. They work in an environment where most of the people around them also carry wireless phones. This probably makes services, such as answer a call on a different extension unnecessary; since they probably are not aware of the extension numbers of the phones nearby as they are always varying. The need of functions such as follow me (internal and external) and free seating may also be of small interest for these users, since they do not have a fixed phone. These functions would therefore not be necessary to include on a sticker with PBX codes to be placed on the back of the phone. For other Wi-Fi users group such as mangers and IT staff, these functions are probably of greater interest.

8.4 Phone Specific Proposals This section presents specific proposals for each Wi-Fi phone. These proposals pinpoint some of the most common usability issues found in phones today.

8.4.1 Hitachi WirelessIP5000 During the usability tests it became obvious that certain things could be changed or replaced on the phone to increase the usability.

8.4.1.1 Improved Button Indications The on/off button should be indicated with a little symbol. The clear-button should also be indicated in a better way, perhaps using a C, like many mobile pho-nes have, or a back-pointing arrow.

Hitachi Proposal: Indicate on/off button with Hitachi proposal: Indicate clear button

8.4.1.2 Web Interface Guidance Add information about the web interface to the phone’s user manual. The user should not be expected to search for the relevant pages in the web configuration manual. This is important since the usability tests showed that the users did not know where to search for help. Furthermore, it is essential that it is mentioned in the manual where the IP address is found.

Hitachi Proposal: Add information about the web interface to the phone’s manual Hitachi Proposal: Mention in the manual, where the phone’s IP address is found.

8.4.1.3 Avoid IP Numbers The users should not be expected to be familiar with IP numbers and port numbers. These numbers are used to be able to login to the phone’s web interface, which as mentioned cause major difficulties for all users. There are two alternative ways of solving this issue. The first alternative is to use the phone number instead of the phone’s IP number, when logging in. This requires a DNS server that interprets the telephone number and looks up the current IP number. The other option is to make the phone’s web address more visible by showing it in the display. For instance http://192.168.0.101:8080 can be shown at the top of the display.

Hitachi proposal: Use the phone’s phone number to log in to the web interface Alternative proposal: Show the phone’s web address in the display

8.4.1.4 Deactivate Unusable Functions Functions in the phone can be deactivated through the web configuration page, making them invisible in the phone’s menu. Since there are several features in the phone that are not compatible with MX-ONE I recom-mend that they are deactivated, to avoid confusion. An example is the presence function.

Hitachi proposal: Deactivate the presence function

8.4.1.5 Unlock the Phone during Calls In Hitachi WirelessIP5000 is not possible to reach the phone book during an active call. As a result, a mobile person wanting to transfer a call or make an inquiry has to know the other person’s extension number by heart. Considering that most of the Wi-Fi users are found in enterprises with several hundred employees, this is pro-bably not the case. Furthermore, this limitation makes it impossible to place the PBX codes for these func-tions in the phonebook, since they are activated during a call. All together, this makes the functions conference call, inquiry and transfer difficult to use. I therefore propose that when choosing between alternative Wi-Fi phones to certify or recommend, one should check whether it is possible to use the phone book during an active call.

Hitachi proposal: Enable phone access during calls.

8.4.1.6 Color Display As mentioned, it would be reasonable that a color display would generate a higher user satisfaction. This is based on the fact that almost all mobile phones today


are equipped with color displays, as well as many of the wireless phones sold to the home users, such as DECT. In a near future, almost all the phones we use will probably be equipped with a color display, making monochrome displays feel unappealing and old. I would therefore propose that Hitachi WirelessIP5000 to be equipped with a color display. It is however im-portant that the display can be used in sunlight as well as in dark environments. Hitachi proposal: Equip Hitachi WirelessIP5000 with a color display.

8.4.2 Ascom i75 The proposals in this section are based on the issues fo-und when comparing Ascom i75 with the other Wi-Fi phones, using the parameters presented in section 7.1.

8.4.2.1 Store PBX Functions in the Phone As I previously mentioned, it is possible to store certain numbers and codes under in the sub menu called services. I recommend that the most common PBX functions, such as certain absence codes (lunch 1 hour, gone for the day) should be stored here. To make them more accessible, one of the soft keys can be used as a shortcut to these services, and can preferably be named Absence. The user then only has to press this soft key and then choose the correct absence reason, to activate the absence feature in the PBX. The phone automatically dials a phone number consisting of the correct PBX absence codes.

Ascom proposal: Store common PBX functions under the services sub menu Ascom proposal: Make one of the soft keys link to the PBX functions

8.4.2.2 Color Display As I proposed for Hitachi WirelessIP5000, Ascom i75 should also be equipped with a color display, to in-crease the user satisfaction. Ascom proposal: Equip Ascom i75 with a color display.

8.4.3 Accton VM1188T During the usability comparison between the three Wi-Fi phones, several usability issues with Accton VM1188T appeared. This section presents proposals of how these issues can be solved, in order to maximize the usability.

8.4.3.1 Avoid System Failure Accton VM1188T’s system easily fails when for instance trying to dial a number when located outside the coverage area. This should be avoided.

Accton proposal: Solve the problems associated with no coverage and performance.

8.4.3.2 Manual Accton VM1188T does not come with a manual. To make it easier for the users to find guidance, a manual for the phone would be preferable.

Accton proposal: Produce a user manual for Accton VM1188T

8.4.3.3 Better Button Indication The on/off button should be indicated with a little symbol. Also, it would be preferable if the menu indi-cation “M” can be replaced with “Menu”. It should also be obvious how to save an entry.

Accton proposal: Indicate the on/off button with Accton proposal: Indicate the menu button with “Menu” instead of “M”

8.5 PBX Related Proposals The proposals in this section concern the PBX functions, and have to do with usability issues that lie outside the Wi-Fi phones. These proposals are there-fore to an increased extent accomplishable by Ericsson Enterprise.

8.5.1 Increase Confirmation & Feedback It is obvious that there is a need of increased feedback to the phone users from the PBX when using a Wi-Fi phone and also other wireless extensions such as DECT phones. Feedback and confirmation can be given in several ways;

(i) Voice confirmation after having entered a command.

(ii) Message sent to the phone indicating that a certain function has been activated.

(iii) Improved confirmation beeps after having entered a command.

I will now present these alternatives more in detail.

8.5.1.1 Voice Confirmation Giving a voice confirmation after having entered a command, such as a PBX code, is probably the best way of giving feedback to the users about the function that they are trying to activate. For instance, after


having dialed 5 to activate call-back, a voice could say “Call-back is now activated. Hang up and wait for the PBX to call you back when the person you are trying to reach is available. Say cancel to inactivate call-back.” By providing such a confirmation, the users are infor-med about what function they have activated; they also know what to do. According to Israelski and Lund (2002), most users expect voice activated services to require less effort than services where the users dial commands upon voice output. As a result, the users should be prompted to say “cancel” rather than press star to inactivate a service. To be successful, the Israelski and Lund (2002) also believe that questions should be followed by the options the user has, such as “Do you want to activate call-back, yes or no?.” The users then know what they can answer. During the usability tests it was obvious that not all users knew what to do when they had dialled 5 when they wanted to activate call-back. Furthermore, this alternative gives the experienced users the option to avoid the confirmation by hanging up directly after pressing 5.

Proposal: Indicate activation of PBX functions with voice confirmation

8.5.1.2 Display Feedback If voice confirmation is not feasible, feedback and confirmation can be given as a message in the display. The users would for instance get a message in the display directly after having dialled 5, informing that call-back is activated, or receive the message after hanging up. This alternative is not as good as voice conformation since it is not immediate, but opens up for more information to be given by sending a long message to the users with instructions.

Alternative proposal: Indicate activation of PBX functions with a message sent to the phone

8.5.1.3 Improved Confirmation Tones The last alternative, if neither of the other two is feasible, is to improve the confirmation tones heard after entering commands. Today, when having entered a command such as absence notice, a chopped dialling tone is heard. During the tests it became obvious that few users understood that this was a confirmation. They were uncertain whether the command was accepted or not, and several users did the same procedure once again. My proposal is to replace these three beeps with two other types of beeps that are more likely associated with good/ok and bad/fail. So if a command is correctly activated, the positive beeps or tones (such as a low pitch followed by a high) will be heard. If the command was incorrect, a more negative

sound should be heard (such as a low pitch followed by an even lower pitch).

Alternative proposal: Replace the chopped dial done confirmation with more appropriate beeps.

8.5.2 Increase Status Awareness If the proposals above would be implemented, the need for increased status awareness would decrease.

8.5.3 Ease or Avoid PBX Codes It is obvious that PBX codes cause confusion and diffi-culty for the users. Either they have to have access to the PBX codes or they have to learn them by heart. Some stationary phones, developed by Ericsson, have overcome this difficulty by adding a menu system or graphical interface often involving soft keys where the available functions are showed on the display. During a call for instance, by pressing one button with the label ‘Transfer call’, the active call is transferred. Further-more, Ericsson’s DECT extensions are often delivered with a quick guide where all the functions are listed as well as a description of how they are activated. Since the Wi-Fi phones are not developed by Ericsson, and can be bought off the shelf without involving Ericsson, there is no simple way of distributing quick guides. Moreover, a quick guide is not optimal for a typical Wi-Fi phone user, since they are mostly mobile not placed at a desk when using the phone. There are several alternative solutions of how to avoid or simplify the use of PBX codes:

(i) Adding the functions to the phone’s menu (ii) Voice Activated Assistant (iii) Web interface for handling some of the

functions (iv) Quick guide (v) Online guidance

These solutions will now be described in more detail.

8.5.3.1 Phone Menu Entries The usability in using PBX functions would be significantly improved if they were added to the phone. This can for instance be implemented by adding the functions to the phone’s main menu or by adding featu-res such as absence notice and voicemail to the phone-book, preferably placed in a specific folder or folders. Many users did not fully understand the separation bet-ween the PBX and the phone. This was also one of the reasons why they did not know where to search for help. All information should therefore preferably be found in one place. This can be solved by adding all the features to the phone’s menu. This however requi-res cooperation with the phone manufacturer.


The option to add functions such as absence codes to the phone book, in a special folder, is a bit limited. It would be impossible to add all absence reasons with all possible times and dates; instead, one would have to evaluate which absence notices are the most common. These numbers should preferably be entered by the telephone administrator. Many of the suffix functions, such as call-back and telephone conferencing, can not be activated this way in Hitachi WirelessIP5000, since locks the phone during calls, so that phone book etc can not be accessed. As mentioned earlier, Ascom i75 has support for adding PBX codes in the phone under the services menu. This makes it easier for the users to activate prefix functions.

Proposal: Add the PBX functions to the Wi-Fi phones’ menus (requires cooperation with the phone manufacturer) or phonebooks (requires cooperation with the telephone administrators).

8.5.3.2 Voice Activated Assistant MX-ONE has a built in Voice Activated Assistant. Currently, this service is mainly for calling persons in corporate directory. When having dialed the number to the voice activated service (for instance 67090) the user is prompted to say the name of the person they want to call, the service than transfers you to this person’s extension. This service has however more functionality than what is apparent. By saying “huvudmeny” or “main menu” instead of saying a name, the users get even more options. For instance they can activate absence notice. Voice activated services is a good way of activating PBX functions for mobile workers. There are however a few issues with the current solution. Firstly, I do not think many people know of this number. Even less know that they can do more things than looking up numbers, by saying “huvudmeny” or “main menu”. Furthermore, the service is rather slow since the voice activated assistant tells you all your options. An experienced user would therefore probably get bored by waiting for so long. My suggestions regarding the voice activated assistant consists of several different layers:

(i) The service should have increased functionality

(ii) The service should be easy to reach (iii) It should be apparent to the users what

options they have/what they can do (iv) The service has to be time efficient

(v) There has to be shortcuts or accelerators for the experienced users.

My suggestion is that there should be one single number that can activate almost all PBX functions. It should be a simple phone number that is easy to dial and remember, such as * or #. After this you can either say what you want to do directly or hear the options, divided into several categories. To activate that I will be out on lunch until 2 o’clock, I can either say “lunch till kl 2” or choose absence notice – lunch - and then say the time I’ll be back. At all steps, the voice activated assistant tells you what alternatives you have and what to do. When having said the command, the voice should then, exactly like it is today, give you a confirmation by repeating what you have activated; “lunch till kl 2”. After the voice activated assistant has confirmed your entry, it would be suitable if the shortcut to this feature is presented so that the user can use this function more efficiently the next time. For instance a message such as “Did you know that you can enter this command by directly saying “lunch till kl 2”?” Furthermore, the menu items have to be short (Israelski & Lund 2002) and the service has to be developed with the context of use in mind. If the service is to be used in hospitals or an industry plant, a high noise level has to be acceptable. Compared to the voice activated assistant of today, I think this service should support more features, such as telephone conferencing, call back, transferring calls etc. During an active call, the user should therefore have the option to dial the number, and then choose what to do. If this is not accomplishable, today’s solution should be modified, so that the voice activated assistant tells you that you can say “huvudmeny” or “main menu” and not only names.

Proposal: Develop a voice activated service where all the common PBX functions (prefix and suffix) can be activated. The options should be divided into several subcategories, to make the service more time efficient Alternative proposal: Modify today’s voice activated assistant, so that it is obvious that you can say “huvudmeny” or “main menu” in the beginning.

8.5.3.3 Web Interface Some of the PBX functions are not directly linked to the phone and could be activated via a web interface. For instance, absence notice and call forwarding. This is however not preferable for users without a desk, but if it is easy to do, for instance via a terminal by the exit or where the phones are stored, it can easily be done on the way in or out of the building. This requires that the web interface is easily accessed, for instance by


logging in through the company’s intranet for instance using the phone number.

Proposal: Develop a web interface that can be used via a terminal where PBX functions, such as absence notice and call forwarding, can be activated.

8.5.3.4 Quick Guide If it is not accomplishable to integrate the PBX func-tions into the phone’s menu or into a voice activated service, it is necessary that the users get easy access to the PBX codes. The Wi-Fi phone will primarily be used by people who are on the move, perhaps not having a desk, or at least spending plenty of time away from it. A quick guide paper would normally have been helpful, but for mobile workers it may not be very suitable. A better solution would be to have a sticker with the most important PBX codes to be put on the back of the phone or on something else that the user carries around the entire time. This sticker would contain the most important PBX functions; call-back, call transfer, telephone conferencing, etc. This sticker-quick guide can be complemented with a foldable pocket-sized quick guide with all PBX codes, and some further assistance regarding the PBX functions. The biggest problem regarding these stickers and quick guides would be to find a way of distributing them. This can preferably be done together with the PBX to the telephone administrator, who can then be respon-sible for distributing them to the end users. This person is apparently in contact with both Ericsson Enterprise

and the end users, since he or she is the one configuring the phones before use. These two types of quick guides are preferably distributed together, by fastening the sticker on the back of the pocket-sized quick guide, and can easily be removed from there to be fastened on the phone. Proposal: Design a foldable pocket-sized quick guide with complete information about the PBX functions and how they are activated. These quick guides are to be distributed together with the PBX via the telephone administrator. Proposal: Design a sticker with the most important PBX codes to be placed on the back of the Wi-Fi phones. This sticker can be distributed together with the pocket-sized quick guide, perhaps glued on the back of it.

8.5.3.5 Online Guidance Many of the test participants requested help to be found online. This web page would contain informa-tion about the PBX have a FAQ and also quick guides etc. This page can preferably be linked from the company’s intranet. Manuals for the phones and the web interface can also be placed here. This proposal is regardless of whether the other pro-posals concerning the PBX codes are implemented.

Proposal: Make guidance available online. The guidance should include FAQ:s, quick guides etc, and should be linked to from the customers’ intranets etc.

CHAPTER 9. DISCUSSION 42

9. Discussion In this chapter there is a general discussion about usability in technical systems. Alternative methods to the one used in this project are also presented as well as recommendations for further studies. 9.1 Usability in Complex Technical Systems The usability test conducted on Hitachi Wireless-IP5000 did not only show what functions and aspects that the test participants had problems with. It also gave me a chance to relate the test participants behavior and results to their previous telephony experience and technical knowledge, etc. The tests revealed that there was no big difference between the experienced PBX phone users and novice users in using Hitachi WirelessIP5000 connected to MX-ONE. It was however evident that the test participant with greater technology knowledge had a greater understanding of the web interface and of where to find the IP address etc. This is probably because they have more correct mental model of the Wi-Fi telephony system including the web interface and can relate to other devices having network connectivity. Moreover, the questionnaire results revealed that the test participant with less technology skills also had greater difficulty in understanding what was handled by the PBX versus locally in the phone. This did however not affect their performance when trying to solve the telephony tasks.

9.2 Results Discussion During this project it has become obvious that the way that PBX functions are to be activated via a wireless phone such as a Wi-Fi phone, is lacking in usability. Many users do not know that the functions exist. Many do not know how to activate them. Furthermore, once having entered a command, many users are uncertain whether the function was activated or not. Proposals of how to solve some of these issues have been presented in this report. Important questions to keep in mind when planning and developing future releases of MX-ONE might be the following;

(i) What functions do we expect the users to use?

(ii) For what? (iii) How can the users become aware of the

useful functions? (iv) How can we make this easier for the

users? This report has concentrated on the last question; how to make it easier for the users. But the other questions are just as relevant. The first two questions, regarding what functions the users are expected to use, should be answered while keeping the actual users in mind. The user group studies have shown that the majority of the expected Wi-Fi phone users are mobile workers perhaps without access to a desk or a computer. The functions that are the most interesting for these users should be prioritized. The third question, concerning the awareness of these functions is also very relevant. Functions can be very easy to use and the users can benefit greatly from them, but will not be used if the users do not know that they exist. Other dimensions may also affect the usage of PBX functions. According to Ericsson’s Consumer and Enterprise Lab (2006), few people use new mobile ser-vices such as sending MMS messages, accessing online services and using the phones calendar function. Still, there is a desire for new services and functions. For instance, approximately 39 % of the working popu-lation believes that they would be more efficient in their work if they have easy access to the company’s phone directory. Moreover, 28 % believe that a presence function, showing who is available, makes them more efficient (Ericsson Consumer and Enterprise Lab, 2006). The conclusion is that people tend not to use certain functions that they believe that


they need. Perhaps is this because of lacking usability or unawareness of these features or mistaken need.

9.3 Method Discussion There is seldom one given way of solving a problem. This applies to small tasks as well as larger projects such as this Master’s project. Concerning usability testing, the methods and choices are endless. Different usability experts have different ideas of how usability tests should be executed, although the goal of increasing a product’s or system’s usability is the same. There are different opinions of what should be tested, who should be tested, where it should be tested, what to be measured and how to analyze the results. The chosen method is often a compromise of a number of factors such as the available amount of time and money and what is possible to do. Many usability experts recommend products and sys-tems to be tested in their natural environment. This was however not technically possible since the PBX was not fully developed at the time of the tests. Whether a real context test would have generated other test results is uncertain. Real context tests cover factors that will influence the use of the product, such as the sound level or humidity. It however results in many factors that can influence the tests that the test leader can not control and may not be aware of. Many tests on mobile phones have been carried out on phone emulators on a computer. The usage of such a system is however very different from regular use of a mobile phone, which is one of the reasons why this was not considered as a possible testing method in this project. Real context tests could however have been used as a complement to the lab tests conducted in this Master’s Project. This would probably have resulted in certain findings that were not found in this Master’s project. If there had been more time available, I believe that it would have been beneficial to include usability tests on Ascom i75 and Accton VM1188T as well, and not only on Hitachi WirelessIP5000. These two phones were however, as mentioned, added to the project at a later stage, which made this accomplishable.

9.4 Validity & Reliability Validity is whether what is indented to be evaluated and measured actually is evaluated. The goal of this project was to establish how high the usability is in using Wi-Fi phones connected to MX-ONE. In the usa-bility tests conducted on Hitachi WirelessIP5000, most of the participants did not use the PBX functions that

were tested on a regular basis. Perhaps more experien-ced users would have given other test results. Studies from Ericsson Consumer and Enterprise Lab (2006) do however show that users generally do not use these telephony functions very much, so this project is to be considered valid. Reliability has to do with whether the method is repeatable and generate the same results. To attain a high reliability the procedures should be described in detail so that they can be repeated. Except for the method description found in chapter 2, all question-naires and the test plan have therefore been attached to the report (see Appendix A, B, C & D). The findings from this Master’s project can partly be applied to other mobile telephony devices communi-cating with a PBX. In 2007, Gartner Group predicts that 85 % of all mobile phones will be equipped with Wi-Fi functionality. The future will tell if this opens up for increased usability or not.

9.5 Recommendations for Further Studies During this project I have encountered subjects and issues related to my work that may be in need of being analyzed, improved or modified. I have chosen to list some of these subjects.

9.5.1 Usage of PBX Functions During my work I realized that PBX functions and the codes to activate these functions could be studied and analyzed further. How much do the users actually use these functions? Is it a matter of usability –finding it too difficult or is it because there is no need? Ericsson Consumer and Enterprise Lab have performed studies where some of these questions have partially been covered, but I am of the opinion that these codes could be the main part of a study.

9.5.2 Usability Tests on Ascom i75 & Accton VM1188T This project included usability tests on Hitachi WirelessIP5000. Ascom i75 and Accton VM1188T were evaluated without any usability tests or end users involvement. The results from the usability tests on Hitachi WirelessIP5000 and the test participants’ input from these sessions did however influence the evalua-tion. Usability tests on Ascom i75 and Accton VM1188T would however probably give more input regarding the usability parameters, such as the users’ subjective satisfaction. These tests could also verify or


disprove the findings in this report regarding the phone comparisons.

9.5.3 Mobile Workers This project was to a large extent based on information from Ericsson staff and from other communications companies. Another approach would be to perform an ethnographic study, where mobile workers are studied in their context of use. This could possibly give a lar-

ger understanding of what telephony needs these work-ers have and their limitations and possibilities. Perhaps there are other solutions rather than mobile phones, such as Wi-Fi phones, that would be more suitable for these workers. Perhaps the functionality found in MX-ONE today should be replaced or expanded with new functions that these workers would benefit from to a great extent.

REFERENCES 45

References Interviews Andersson, Christer (2006). BES/ADP, Ericsson Enterprise, 2006-07-13 Avesand, Stefan (2006). Ericsson Enterprise, 2006-07-05 Berggren, Lars (2006). Sales & Marketing, Ericsson Enterprise, 2006-06-27 Dahlqvist, Peter (2006). BES/ADP, Ericsson Enterprise, 2006-07-13 Höglander, Mats (2006). Mobility Manager, Ericsson Enterprise, 2006-06-19 Junthé, Marcus (2006). Sales & Marketing Ericsson Enterprise, 2006-06-27

Other References Andersson, Björn, Ericsson Enterprise Hindersson, Lars, Ericsson Enterprise Holm, Anders, Ericsson Enterprise Kjebon, Fredrik, tutor, Ericsson Enterprise Severinson Eklundh, Kerstin, tutor, Royal Institute of Technology (KTH) Åström, Per, Nova Project Manager, Ericsson Enterprise

Reports, Books & Articles Ahsan, S. & Ahmad, S. (2005). Using Voice over IP and a Wireless Network to aid Collaboration in the Construction Industry,

Bergqvist, J. (2000). ComCenter: A Personal Oriented Approach to Mobile Communication. CHI 2000, 1-6 April, p 123-124. Beyh, S. & Kagioglou, M. (2004). Construction sites communications towards the integration of IP telephony, Salford Centre for Research & Innovation (SCRI), SCPM, the University of Salford, UK Bingert, C. (2003). Mobila tjänster i vardagen – En studie med fokus på nyttan och värdet i mobila tjänster, Master’s thesis at Royal Institute of Technology, Stockholm, HCI department Bowden, S. L. (2005). Application of Mobile IT in Construction, Lounghborough University. Brodie, J. & Perry, M. (2001). Designing for Mobility, Collaboration and Information Use by Blue-Collar Workers, Brunel University, Siggroup Bulletin Dec 2001, Vol. 22, No. 3, p 22-27 Bubley, D. (2005). VoWLAN Business Models – How the wireless VoIP market catalyses fixed mobile convergence, Summary, Disruptive Analysis. Cadiz, J. et al. (2004). Exploring PC-telephone Convergence with the Enhanced Telephony Prototype, CHI letters 2004, April 24-29, p 215-222. Chae, M. & Kim, J. (2004). Do size and structure matter to mobile users? An empirical study of the effects of screen size, information structure, and task complexity on user activities with standard web phones. Behaviour and Information Technology 2004, Vol. 23, No. 3, p 165-181 Chittaro, L. & Dal Cin, P. (2002). Evaluating Interface Design Choices on WAP phones: Navigation and Selection, HCI Laboratory, Personal and Ubiquitous Computing 2002, No. 6, p 237-244.

REFERENCES 46

Disruptive Analysis (2005). VoWLAN Business Models: How the wireless VoIP market catalyses fixed-mobile convergence. Summary. Ericsson Consumer and Enterprise Lab (2004). New Communication Solutions for Working People in China, US, Italy –Mobile Worker Ethnographic Research. Prepared by Renis Rahn. Ericsson Consumer and Enterprise Lab (2005). Profiles of 10 working groups – extract from Report on Communication Habits and Needs of Working People 2004. Prepared by Renis Rahn. Ericsson Consumer and Enterprise Lab (2006). Communication habits and needs of working people 2005, Prepared by Kristina Sandklef and Renis Rahn. Fallman, D. (2002). Wear, Point, and Tilt, designing support for mobile service and maintenance in industrial settings, DIS2002, London Faulkner C. (1998). The Essence of Human-Computer Interaction, Prentice Hall, USA Grufman, H. (2005) An analysis of future development of Voice over IP with emphasis on Wireless solutions, Master’s Thesis at Chalmers’ Department of Signals and Systems, executed at Atos Origin Halvorsrud, R. & Sund, T. (2005). The use of mobile telecommunication in Norwegian hospitals, Scientific Report, Ho, J. et al. (2001). A Conference Gateway Supporting Interoperability Between SIP and H.323. MM’01 September, p 421-430. IDC (2003). Market analysis – Part one: the end user survey and cluster analysis, Ericsson, IDC opinion Anna Bager.

Intersil (2001). Intersil’s PRISM WLAN Chip Set and SpectraLink’s VoIP Technology Improves Communications at One of London’s Major Hospital, http://www.intersil.com/pr/shell/0,1091,556,00.html, accessed 060908 Israelski, E. & Lund, A. (2002). The evolution of human-computer interaction during the telecommunications revolution, The Human Computer Interaction Handbook – fundamentals, evolving technologies and emerging applications.

Jiang, W. et al. (2001). Towards Junking the PBX: Deploying IP Telephony, Nossdav’01 june 25-26 2001, p 177-185. Jokela, T. et al. (2003). The Standard of User-Centered Design and the Standard Definition of Usability: Analyzing ISO 13407 against ISO 9241-11. Oulu University. Mathiasson, L. & Mälarberg, K. (2001) IP-telefoni – 2000-talets kommunikationsmedium, Master’s thesis at Chalmers’ Computer Science Department, executed at Kipling System Integration. Norman, D. (2002). The Design of Everyday Things, Basic Books, USA Palen, L. & Salzman, M. (2002). Beyond the Handset: Designing for Wireless Communications Usability. ACM Transactions on Computer-Human Interaction 2002, Vol. 9, No. 2, p 125-151. Perry, M. et al. (2001). Dealing with Mobility: Understanding Access Anytime, Anywhere, ACM Transactions on Computer-Human Interaction, Vol. 8, No. 4, December 2001, Pages 323–347. Person, R. & Vitella, J. (2005) Enhanced Multi Media Adaptor (Emma) project, Master’s thesis at Royal Institute of Technology, Stockholm, NADA department, executed at Ericsson Enterprise Preece J. et al. (2002). Interaction Design – Beyond human-computer interaction, John Wiley & Sons, Inc., USA Rubin J. (1994). Handbook of Usability Testing, John Wiley & Sons, Inc., USA

REFERENCES 47

SpectraLink (2003). Wi-Fi Telephony – Wireless Voice over IP Presents New Opportunities, Challenges, Spectralink Wireless@work white paper. SpectraLink (2004). VoWLAN – Voice: The Killer App for Wireless LAN, Spectralink Wireless@work white paper. Svensson, C. (2005) Operator = Live Phonebook, Information Provider or Secretary? – A study of telephone operators and the usability of their computer interface, Master’s Thesis in Human computer Interaction at Royal Institute of Technology, Stockholm. Veer, van der, G. C. & Melguizo, M. C. P. (2002). Mental Models, The Human Computer Interaction Handbook – fundamentals, evolving technologies and emerging applications. Weiss, S. (2002). Handheld Usability, John Wiley & Sons Ltd, England Ziefle, M. (2002). The Influence of user expertise and phone complexity on performance, ease of use and learnability of different mobile phones, Behaviour and Information Technology 2005 Vol. 21 No. 5 p. 303-311.

Sales Material & Other Material Ascom (2005a) On-site wireless communications for smoother patient flow- How better communications between departments and quicker response to critical information improves healthcare quality and productivity, and increases patient satisfaction. Ascom (2005b) On-site wireless communications for quicker response - How quicker response to disturbances creates a more agile organization, prevents production losses and reduces risk. Ascom (2005c) Obs! Bergvik, Karlstad, Sweden, the supermarket now offers increased customer service, the staff experiences a safer working environment and more shoplifters are caught in the act. Cisco (2003). Cisco Helps American Savings Bank Reduce Costs, Improve Productivity, and Enhance Customer Service, Customer Profile. Nortel (2005). Improving customer responsiveness with the Nortel Voice over WLAN solution, Solution Brief Hitachi IP 5000 User Guides Ascom i75 User Manual & Quick Reference Guide

APPENDICES 48

Appendices The appendices found in this report are presented below.

Appendix A: Test Plan Appendix B: Screening Questionnaire Appendix C: Post-task Questionnaire Appendix D: Post-test Session Questionnaire

APPENDICES 49

Appendix A: Test PlanA1. Introduction This is the test plan for the usability tests involving a Wi-Fi phone (WirelessIP5000) and a MX-ONE IP PBX. The test plan covers the following sections:

(i) Purpose (ii) Problem statements (iii) User groups (iv) Method (v) Task list (vi) Test environment and equipment require-

ments (vii) Test monitor role (viii) Evaluation method (ix) Test report contents and presentation

A2. Purpose The main purpose of the tests is to establish how user friendly it is for a typical user to use functions in the MX-ONE PBX using the Wi-Fi phone WirelessIP5000. The participants are to perform some of the most common telephony functions, and he/she will be carefully monitored to establish what works well and what needs to be improved. It is obvious that the users have to know the PBX function codes by heart or have access to them in a quick guide or other means to be able to use the PBX functions using a Wi-Fi phone. A quick guide with the most common codes will therefore be handed to the users a day before the test session, together with the phone manual.

A3. Problem Statements These usability test sessions are aiming to answer the following questions:

(i) Is it obvious for the users how to perform certain tasks, such as parking a call and starting a telephone conference?

(ii) How do the users tackle difficulties? (iii) What works well? (iv) What needs to be improved? (v) Do users with greater telephony

experience find it easier to use the telephony functions?

(vi) Do the users use the manual for the phone? Does it help them?

(vii) Do the users use the quick guide for PBX services? Does it help them?

(viii) Can the users differentiate the telephone from the PBX and the rest of the telephony system?

A4. User Groups The tests will be performed during the weeks 35-38 2006 and will involve eight to ten participants. A maximum of three tests will performed per day. Since a majority of the Wi-Fi phone users probably will be former DECT users and that the Wi-Fi phones initially will be used for the same things as the DECT phones, the participants will be divided into two groups according DECT experience. Group one will consist of four to five experienced DECT or mobile extension users who have a mobile job moving around within the office premises. They are supposed to be reachable during the entire working day, and therefore are in need of a wireless phone. They are somewhat familiar with using PBX functions from their current wireless phone. Group two will consist of four to five novice users. All though these users use mobile phones and regular phones in their daily lives, they will still represent the least experienced users when it comes to using PBX functions from wireless devices such as DECT or Wi-Fi phones. The both groups will be performing the same tasks.

A5. Method The usability tests will consist of four different parts that now will be described more thoroughly.

A5.1 Participant Recruiting & Screening When searching for participants for the test sessions, the two user groups presented above will be used. As previously mentioned the first group of users is currently using DECT or mobile phones at work and are mobile during working hours, spending time away from their desks. The other users are totally unfamiliar with DECT phones connected to a PBX. This inexperienced group will be recruited among my associates from school. The DECT users will be recruited from Ericsson Enterprise, and will consist of people who have not been involved in the development of the MX-ONE PBX. I will use a screening questionnaire when trying to find the right users. When I have found users that match these profiles they will be invited to participate in the usability tests. At this stage, they are also briefly informed of the usability tests, that they will be recorded and what the purpose is. The phone manual and PBX codes will be mailed to the users a day before the test.

APPENDICES 50

A5.2 Participant Greeting & Introduction When the participants arrive to the test session, I will greet them and brief them about the Master’s thesis and the reason why they are there. They will be told what is expected of them and that the telephony system is what is actually being evaluated, and not them. The participants will also be told that they will be observed and recorded (sound and video) and that they should try to act and solve difficulties as they normally would but try to use the think aloud technique. This will be used to capture their thoughts, intentions, frustration, delight and confusion. I will demonstrate how this can be done. Since the predicted, typical Wi-Fi user will not have any prior training before using their new Wi-Fi phone, neither will the test participants.

A5.3 Test Session The test sessions will be carried out as follows: I will accompany the test participant into the test room and show him or her the Wi-Fi phone. Since the phone will be recorded, instructions will be given of how to hold the phone. I will then exit the room. In order to feel more relaxed in the test room, the participant will be asked to start the phone and use it freely for a couple of minutes before the test begins. The test person will, however, be monitored during this time as well. In order for the test person to hopefully forget that she or he is being observed, the use of the intercom system between the observation and test rooms will be avoided as much as possible. The test person will be informed of their telephone number and other relevant information that is needed to be able to perform the tasks. The tasks will then be

presented on paper, one at the time. On the table there is a phone with a charger, hands free, a quick guide for the PBX codes and a handbook for the phone. The telephone will be preprogrammed so that it communicates with the MX-ONE IP PBX, as this probably in most cases will be done by telephone administrators and not the end users. The test session consists of a series of tasks with varying complexity that reflects the most common functions among the target groups. The first tasks are designed to be rather simple. After some of the more complex tasks, such as setting up a telephone conference, there will be a questionnaire, with a few questions. If the test person encounters difficulties solving a task, guidance will be given via the intercom system. The test sessions will be recorded and monitored and will take about 30-60 minutes per participant. During the test sessions, the elapsed time for each task will be noted, as well as relevant events and behavior.

A5.4 Participant Debriefing After each test, the participant is asked to leave the test room and fill in a questionnaire about his or her perceptions of the test sessions, the tasks and the telephony use. He or she will be debriefed by the test monitor about the test to collect his or her comments and discuss them more thoroughly. Unanswered questions from both sides will now be answered. The participant will then be thanked for their effort and receive a small token of appreciation.

A6. Task List The tasks will be presented one by one. If the users meet difficulty, not all tasks will be performed. The users will be given the following information:

APPENDICES 51

Task no. Task Description Task Detail How to do this

PRETEST

0 Start the phone Slå på telefonen och logga på. Håll in “END” I några sekunder

0 Get familiar with the phone Bekanta dig med telefonen i ett par minuter.

TEST

1 Make an external call Ring Fröken Ur och notera tiden. Lägg sedan på. Tryck 00 90 510 “SEND” Lägg på genom att trycka “END”

2 Make an internal call

Ring till Kontrollrummet. Lägg på efter ett kort samtal. Tryck 67 801 ”SEND”. Lägg på genom att trycka ”END”

3 Populate the phone book

Lägg in numret till Kontrollrummet i telefonboken och spara.

Alt 1: Via call list:

tryck vänster ”received calls” ”options” – spara med mittenknappen.

Alt 2: via telefonbok:

“menu” – “1. Phonebook” – ”2. New number” fyll i , mittenknappen f spara.

Post-task questionnaire

4

Park call

När Kontrollrummet ringer och vill veta tiden svarar du för att sedan parkera samtalet och ringa Fröken Ur. Återkom sedan till Kontrollrummet med tiden. Avsluta sedan samtalet.

Could not be tested

Byt till datorskannern

5 Webb interface Gå in på telefonen via dess webbgränssnitt, och lägg därgenom Fröken Ur:s telefonnummer i telefonboken.

Hitta telefonens IP-nummer (”menu ”- ”setup” – ”information” – ”TCP/IP” under IP address) och skriv in adressen m portnr: 130.100.250.191:8080 i en webbrowser. Logga in med user/0000 ”phonebook” – ”new number” fyll i och sedan ”SAVE”.


6 Transport call Ring Fröken Ur och transportera samtalet till Fredrik. Could not be tested

7 Use voice mail Ring till din röstbrevlåda och lyssna av dina eventuella meddelanden för att sedan avsluta samtalet.

Skriv 67 777 ”send” följ instruktionerna

OBS- RING SÅ ATT DET BLIR UPPTAGET I KONTROLLRUMMET

8 Call back

Ring till Kontrollrummet igen för att berätta vilken veckodag det är. Om det är upptaget, aktivera återuppringsfunktionen. När du fått tag på Kontrollrummet, och meddelat vilken veckodag det är, avsluta samtalet.

Ring Kontrollrummet via call list (höger) el telefonbok. Vid upptagenton, tryck ” 5”, sedan ”end”. När det ringer, svara och vänta.

9 Telephone conference

När Kontrollrummet ringer, svara och starta sedan en telefonkonferens där även Fröken Ur ingår. Lägg sedan på.

Could not be tested

10 Absence Lämna besked om att du ska vara upptagen i möte till 17.30. Tryck *23*3*1730# ”send”


11 Shut down Stäng av telefonen. Tryck ”end” i några sekunder.

APPENDICES 52

A7. Test Environment & Equipment Requirements The tests will be performed in Ericsson Enterprise’ Usability Lab. The participants will be filmed by two cameras and be monitored through a one-way mirror. To be able to perform the test session, a telephony system will been installed partly consisting of; one MX-ONE 3.0 PBX, one WirelessIP5000 Wi-Fi phone (to be tested), a wireless access node and one phone installed in the observation room, to be able to perform the tasks that involve parking and forwarding calls as well as setting up a telephone conference. To feel less laboratory-like, other props such as a com-puter, pens, paper and plants will been placed in the test room.

A8. Test Monitor Role During the test, I will function as a test monitor located in the observation room together with other observers. I will take notes of the participant’s actions and per-formance and assist him or her if needed. The partici-pant will, however, not receive any assistance if he or she does not get stuck or asks for guidance. If assis-tance is given, this will be noted. In addition to the monitor there will always be at least one other person in the observation room during the tests. If the test participant gets stuck, guidance will first be given via the intercom system. If the participant

needs further guidance one of the persons in the obser-vation room will be able to enter the test room, to assist.

A9.Evaluation Measures The following will be measured, noted and collected during the test sessions:

(i) The time it takes to complete each task. (ii) How the participant tries to solve the

tasks. (iii) What works well (iv) What does not work so well (v) The participants’ thoughts and reflections. (vi) How much they use the phone’s manual (vii) How much they use the quick guide

A10. Report Contents & Presentation In week 37 a short report of the first findings from the test sessions will be finished. The report will include the following:

(i) Test Plan (ii) Results from the first test sessions

In week 38 there will be a presentation where this information will be presented orally. The user and customer groups will also be presented. In the Master’s thesis report that will be finished in week 48, all results from all the test sessions will be presented, as well as proposals to how the usability can be increased. This will be presented orally to the concerned staff at Ericsson Enterprise in week 46.

APPENDICES 53

Appendix B: Screening Questionnaire Namn: Sysselsättning: Ålder: Kön: Utbildning: Ange din användningsvana för följande typer av anslutningar: (Kryssa i) Aldrig använt Ovan Van Väldigt van

Fast hemmatelefon

Trådlös hemmatelefon

Mobiltelefon

Fast telefon ansluten till växel

Trådlös telefon ansluten till växel

Mobiltelefon ansluten till växel

Annat:

Ange hur ofta du använder följande telefonifunktioner i ditt nuvarande jobb! (Kryssa i) Några ggr per år eller

mer sällan Några ggr i månaden Någon/Några ggr i

veckan Någon/Några ggr per dag

Parkera samtal

Återuppringning

Initiera telefonkonferens

Frånvarobesked

Transportera samtal

Annat:

Ringer du till telefonist (09)? Om ja, hur ofta och för vad?

APPENDICES 54

Appendix C: Post‐task Questionnaire Denna uppgift anser jag vara: Lätt Ganska lätt Ganska svår Svår

Denna del av uppgiften hade jag inga problem med (förklara gärna):

Denna del av uppgiften tyckte jag var extra knepig eller förvirrande(förklara gärna):

APPENDICES 55

Appendix D: Post‐test Session Questionnaire Finns det något som du upplevde som extra svårt?

Vad ansåg du fungerade bra?

Vad tror du hände med ditt frånvarobesked när du stängde av telefonen? Vad skulle du göra om du inte hade quickguiden med koderna?

Om du hade ett mobilt arbete, där du inte satt still vid ett bord, hur skulle du vilja ha tillgång till koderna?

Vad tyckte du om telefonens webbgränssnitt? Bra? Dåligt? Svårbegripligt? Motivera gärna

Om du ägde en Wi-Fi-telefon, tror du att du skulle använda telefonens webbgränssnitt? Till vad? Hur ofta?

Hur anser du att man skall nå och få hjälp?

Var och på vilket format bör online hjälp finnas?

APPENDICES 56

Var skulle du förvara manualerna för telefon och system? Vilken hjälp bör man få att hantera telefonen?

Vad tror du sköts av telefonväxeln kontra lokalt i telefonen, med avseende på de uppgifter du just genomfört. Sköts/sker i telefonen: Sköts/sker i växeln: Vad anser du Wi-Fitelefonen du just använt vara mest likt? Ringa in!

(i) En mobiltelefon (ii) En trådlös telefon för hemmabruk (iii) En fast telefon för hemmabruk (iv) En IP-telefon (exempelvis Skype-telefon)

Förklara gärna!

Hur skiljer sig denna telefon från andra typer av telefoner du tidigare använt? Förklara så detaljerat som möjligt!

Vad borde vara inlagt i telefonen vid leverans till användaren? På en skala mellan 1 och 10 – hur användarvänligt tycker du att det var att utföra de förutbestämda testuppgifterna på en Wi-Fi-telefon? Tror du att du skulle behöva hjälp från en tekniskt kunnig person för att kunna använda telefonen och dess funktioner? Motivera gärna! Har du några förslag hur användning av och interaktionen med Wi-Fi-telefonen och växeln kan underlättas?

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wi-fi phone usability and utility - kth

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