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Notes on Review QuestionsNotes on Review Questions for Chapter 1REVIEW QUESTION 1.1

What is the difference between the terms ‘user interface’ and ‘human–computer interaction’?

Historically, the term ‘user interface’ has been used to describe the physical aspects of a computer system that the user experiences directly. Chiefly, these include the interaction devices for input and output and the way in which the communication takes place between the user and the system. ‘Human–computer interaction’, however, is a much broader term and refers to all aspects that impinge on the way in which users interact with computer systems. The disciplines that make up HCI are computer science, psychology, ergonomics and human factors, artificial intelligence, engineering and design, as well as philosophy, sociology and anthropology.

REVIEW QUESTION 1.2

What is the importance of good user interface design? What are the potential consequences of poor user interface design?

Good user interface design is important for several reasons. It can bring about benefits such as reduced costs, improved productivity and efficiency, and reduced employee stress and absenteeism. Training costs may also be reduced. Many benefits, though, are largely hidden and cannot be quantified. Another important factor is safety: some kinds of computer systems can endanger life if their user interface is poor.

Poor user interface design costs businesses and users money. In business, frustration with technology can lead to stress and higher staff turnover. Training costs may also be excessively high when UIs are difficult to use and do not support users in their tasks.

Notes on Review Questions for Chapter 2REVIEW QUESTION 2.1

What are the main advantages and disadvantages of direct and indirect observation?

Direct observation is straightforward and easy to carry out, but you cannot record everything that is happening. Indirect observation allows you to create a permanent record of what you have observed, but takes a long time to analyse.


List the main activities involved in gathering requirements.

The main activities involved in gathering the requirements are as follows.

Understanding the users. This involves finding out about their age, gender, educational background, and so on.

Understanding the environment. This involves discovering whether the environment is light or dark, warm or cold, pressurised or relaxed, and so on.

Understanding the domain. This involves finding out about the task domain.

Understanding the tasks. This involves discovering whether the task is performed frequently or only occasionally, is urgent or nonurgent, and so on.

Task analysis. This includes analysing how the task is performed on the present UI, using techniques such as scenarios, concrete use cases and cognitive walkthroughs.

Understanding the non-functional requirements, such as cost and technical constraints.

Prototyping the requirements, using low-fidelity prototypes such as storyboards.

REVIEW QUESTION 3.2

Bargain Foods is a discount supermarket that uses laser scanning technology for reading barcodes on grocery items. Who would be the real users of the system? Who would be the secondary users of the system?

The real users of the system would be the cashiers who are employed to work the cash tills. Secondary users or stakeholders would be the customers who shop at Bargain Foods. Other secondary users would be store managers, who may use the tills infrequently for tasks like correcting errors or making refunds. Stock clerks would also be secondary users, as they would use the information about items sold to order replacement stock. (For larger stores this may be an automated process, whereby the computer system creates a stock order on the basis of goods sold.)


Define the terms goal, task and action.

A goal is an end result to be achieved. It must be described at a particular level of abstraction, i.e. a high level of abstraction description indicating what is to be achieved. The specific details of how it is to be achieved are not stated.

A task is a structured set of related activities that are undertaken in some sequence. Tasks are what a person has to do (or thinks he has to do) in order to accomplish a goal.

An action is defined as an individual operation or step that needs to be undertaken as part of the task.

REVIEW QUESTION 4.2

What is a mental model?

A mental model is a dynamic mental representation that allows people to make predictions about future states, make inferences and imagine situations that have not been experienced before.

REVIEW QUESTION 4.3

Give the three main differences between structural and functional models.

A main difference between functional models and structural models is that the former develop from past knowledge of a similar domain while the latter have to be learned. Another difference is that functional models are aimed at answering a set of task-related questions whereas, hypothetically, structural models can be used to answer unexpected questions and make predictions. In addition, functional models are context dependent and hence easier to use, whereas structural models are largely context-free, making them easier to extend and integrate with other knowledge.


What is the difference between a design principle and a design rule?

A design principle is a high-level (i.e. abstract) guide for design. Because of their high level of generality, principles are difficult to apply as they must be interpreted and then translated into specific design rules before they can be applied. ‘Be consistent’ is an example of a design principle.

Design rules are low-level, specific instructions that can be followed with minimum interpretation or translation by the designer. Because they are so specific, they are only applicable in relation to a particular system platform, for example in commercial style guides. You will also find company-specific house or corporate style guides, though these are often considered to be commercially sensitive and not freely available.

REVIEW QUESTION 5.2

Figure 1 is an illustration of the home page for the OU Learner’s Guide website. How well does it support the laws of proximity, similarity, closure and continuity?

Figure 1 The OU Learner’s Guide

Proximity and similarity. The words on the left-hand side of the screen are positioned close together in a column. This proximity means that we see them as a group. This effect is reinforced by the use of the same font, font colour and background colour.

The circular icons in the centre of the screen are fairly close together. Whilst the images are different, they are the same size and have the same border. Thus, they appear as a group of icons from which we can select.

Each circular icon has a line coming out of it, with a small circle on the end. This draws the eye to the associated text. The text is also close to the small circle, indicating that it relates to the particular icon.

Closure. The words on the left-hand side of the screen are on a blue– green background. The top border of this area is divided by the Learner’s Guide icon, but we perceive the border as a continuous line with the icon on top: we fill in the gap.

Continuity. We perceive the words in each line of text at the bottom of the screen as being continuous sequences of words, rather than separate words that do not relate to each other.

REVIEW QUESTION 5.3

Define visibility, affordance and feedback.

Visibility. For a control to have good visibility, it should be obvious what the control is used for.

Affordance. To have good affordance, a control should suggest how it is to be operated.

Feedback. To have good feedback, a UI should give information to the user about the current state of the system and what her particular action has achieved.


What kinds of prototyping could be useful during the early stages of system development, i.e. during requirements gathering?

Low-fidelity prototypes, such as storyboards, sketches and other paper-based techniques, would be useful. These prototypes are quick and cheap to produce and give you something visual to discuss with users when gathering requirements. They also facilitate communication between the UI designer and users and stakeholders.

REVIEW QUESTION 6.2

List the types of things you will be assessing in (a) early evaluation, and (b) late evaluation.

During the early design stages evaluations tend to be done for the following reasons.

To predict the usability of the product or an aspect of it.

To check the design team’s understanding of users’ requirements by seeing how an already existing system is being used in the field.

To test ideas quickly and informally, as part of envisioning a possible design.

Later on in the design process the focus shifts to the following activities.

Identifying user difficulties so that the product can be more finely tuned to meet their needs.

Improving an upgrade of the product.


Look back through Chapter 7 and list the characteristics of the approach that Tokairo took that lead to their success in gathering user requirements.

Tokairo visited a selection of drivers, observing their working environment and the tasks they need to carry out. This helped them to identify various groups of users, each with its own requirements.

They involved all the main stakeholders in the early discussions. In addition to members of Tankfreight head office, they also included representatives of the drivers and driver foremen.

They took an iterative approach to gathering the requirements.


What are the benefits of good UI design?

The benefits of good UI design can include increased productivity, lower staff turnover, higher staff morale and job satisfaction, lower operating costs and reduced training needs.

REVIEW QUESTION 8.2

Define task scenario, use scenario, concrete use case and essential use case.

A task scenario is a personalised, narrative description of a task, describing the use of an existing UI.

A use scenario is a personalised, narrative description of a task, describing the anticipated use of a new UI.

A concrete use case is a detailed description of a task. It is similar to a task or use scenario, but it is depersonalised and structured into two columns: user actions and system responses.

An essential use case is a high-level description of a task. It is similar to a concrete use case, but it is at a higher level of abstraction, and the two column headers are user’s purpose and system responsibility.

Thus it is more concerned with what the user and system responsibilities are (or will be) rather than how they are achieved.

REVIEW QUESTION 8.3

Define task object, class and child object.

A task object is a unit of information or data with which the users interact to carry out their tasks.

A class is a type of task object which groups other task objects that have common attributes.

A child object is a task object that is the attribute of another task object.

REVIEW QUESTION 8.4

Define content diagram, container and link.

A content diagram is a low-fidelity prototype that represents the organisation and structure of a UI from the designer’s perspective.

A container is an abstract representation of a part of the user’s work and the functions that are required to do that part of the work.

A link is an abstract representation of how the functionality should be organised in a UI. The links represent how a user will navigate between the functional areas within the UI.


Define the design principles: simplicity, structure, consistency and tolerance.

Simplicity. It is important to keep all aspects of a UI as simple as possible, using actions, icons, words and user interface controls that are natural to the users, and avoiding unnecessary features or other clutter.

Structure. Features that users think of as related should appear together on a UI, or at least they should be clearly and closely associated. Those features that are unrelated, either in terms of work or in the minds of the users, should be separated or distinguished on the UI.

Consistency. It is important to be consistent in appearance, placement and behaviour throughout the UI. This is because a user develops a mental model of the user interface and then uses the model to predict how subsequent screens will appear and how the user interface will behave.

Tolerance. The UI should be designed to prevent users making errors, and to let them recover easily when they do make them.


What is a metaphor? What are the limitations of metaphors?

Metaphors are words, icons or interactive graphics designed to draw upon the users’ existing knowledge in order to enable him to formulate an accurate mental model of a UI.

Metaphors may not match the users’ experience of the world, or they may relate to objects or concepts that are outside the users’ experience.

REVIEW QUESTION 10.2

How might the two main limitations of metaphors affect the usability of DM interfaces?

If a DM interface uses a metaphor that does not match a user’s experience of the world, she will become confused when it does not behave in the way she anticipates. If a DM interface uses a metaphor that is outside her experience, she will be unable to draw on her existing knowledge and hence will have difficulty using the interface.


Which of the five interaction styles is likely to be the most appropriate for each of the following examples?

1. A travel agent entering details about a customer’s requirements for a holiday.

2. A multimedia encyclopaedia requiring users to explore the environment, play audio clips, and so on.

3. Searching a database using a formal query language, such as SQL.

4. A bank ATM, in which a user has to choose from a number of options.

1. Form-fill. The travel agent will enter the customer’s details into the various fields in the form.

2. Direct manipulation. Thus will enable the users to interact directly with the documents and audio clips, moving around the encyclopaedia until they find the required information.

3. Command line. SQL is a formal language, so this can be converted into a command language for searching a database. This will allow the user to specify her requirements very accurately.

4. Menu selection. There are only a limited number of options, so it easiest for the user just to choose the one he wants.

Notes on Review Questions for Chapter 12 REVIEW QUESTION 12.1

Suppose that a keyboard or keypad was to be used for a road survey, to assist in the task of recording the number and types of vehicle that pass a particular roundabout. What type of keyboard or keypad would you choose for this situation? Describe your choice in terms of the following considerations.

Key size.

Robustness.

The keys that are needed.

Assume that cost is not a consideration.

In this discussion we assume that the keyboard or keypad is integrated into a computer device with one or more complementary output devices.

Key size. The keyboard or keypad would need to be easy to handle as there are unlikely to be any flat surfaces and the surveyors may be standing. Thus it will need to be held in one hand, whilst the other hand does the typing. As a consequence, the keys will need to be reasonably large and the keyboard light to carry.

Robustness. It will need to be robust as the work takes place out of doors, with the possibility of rain and snow. It may also be dropped.

Keys that are needed. As there are a relatively small number of different inputs, it might be worth restricting the number of keys and designing a special keypad. This would enable the surveyors to enter data more quickly and accurately. Once they became proficient, it might be possible for the surveyors to keep their eyes on the road and not look repeatedly at the input device.

The simplest solution would be to have a keypad with a separate key for each type of vehicle being counted. This would mean that recording each car would require a single key press.


Specify a screen type for the following devices. Describe your choice in terms of technology (LCD or CRT), resolution, screen size, portability and available space.

A mobile telephone. The screen will indicate when the telephone is connected to the network, the number being dialled, and so on. It is likely to be used in all types of situation, including at night and in the rain.

A desktop computer. The screen will be used to display complex 3D graphics in a design studio. It is likely that several people will want to look at the design at any one moment.

Mobile telephone. The most appropriate type of screen is likely to be an LCD. Such screens are physically light and they consume batteries relatively slowly. Resolution can be quite low as the screen will probably only need to display text and numbers (unless the telephone is used to browse the web, in which case the resolution will need to be higher). Traditionally, telephones have been black and white (unless the telephone is used for web browsing, in which case colour may be needed). The screen size will need to be quite small, as the device is portable.

Desktop computer. Traditionally, large CRTs with a high resolution and million of colours have been used for this type of scenario. This is because the screen does not need to be portable and it is necessary to look at very complex and colourful images. These CRTs can take up a lot of room. If space is a problem, it might be worth investigating large LCDs.


List two lights and a gauge that might be needed for a digital camera. Specify the lights in terms of colour, brightness and frequency of flashing.

A light could flash, indicating that the camera is on. This would provide reassuring feedback, confirming that the camera is working correctly. The colour and rate of flash of the light are not important.

A second light could come on when the camera is ready to take a photograph. In some cameras, this happens when the button is half depressed and the automatic focus is locked in. The light could be green indicating that the camera is ready to go. It should not be too bright as it will need to be positioned near to the viewfinder, where the photographer’s eye will be.

A gauge could be used to indicate the battery level. The gauge could be a series of blocks displayed on a small LCD screen on the top of the camera.


Figure 2 illustrates a screen containing some text. Use the guidelines to give a critique of this screen, explaining how it should be changed in order to make it more legible.

Figure 2 Text that is difficult to read

The following describes how we would modify the text.

Typeface. A serif typeface (Times New Roman) was used in the original. We would change it to a sans serif typeface such as Arial.

Type size. The type size is too small in the original; we would make it bigger.

Letter spacing. This is reasonable.

Interline spacing and line length. The lines are excessively long in the original; we would reduce the line length to around 60 characters. We would also increase the interline spacing to improve legibility.

Justification. We would make the right margin ragged in order to avoid any problems with the inter-word spacing or hyphenation.

Line endings. Where possible, we would try to make line ends coincide with grammatical boundaries (i.e. a single idea or concept to each line of text). This may result in a considerable variation in the line length.

Paragraph spacing. There is only one paragraph, but it is rather long, so we would split it into two.

Figure 3 shows what the text would look like if we applied these decisions.

Figure 3 Text that is easier to read


Table 1 contains some colours and possible connotations. Do you agree with these connotations? Taking into account these connotations and the colour intensity, suggest a background colour for the following e-commerce websites.

A site to sell CDs to young people under 25. The site aims to be exciting and trendy.

A site to sell outdoor clothing to walkers.

A site to sell expensive jewellery to older people.

Table 1 Connotations of different colours (Götz (1998) with modifications by the authors)

Colour Positive connotations Negative connotations

Red Active, invigorating, exciting, Aggressive

powerful, strong, energetic, attractive, dominating

Blue Controlled, abstinent, mysterious, intellectual, harmonious, deep, dreamy, faithful, rational, sensible

Aggressive, introverted cold, melancholic

Blue/Green/Turquoise Refreshing Aloof, self-willed, unemotional, cold, sterile

Green Refreshing, harmonious, optimistic, close to nature, calm, gentle, conciliatory, strong-willed

Jealous, envious, inexperienced

Yellow Colourful, extrovert, cheerful, youthful, lively, full of fun, light

Superficial, exaggerated, vain

Orange Exciting, direct, joyful, alive, communicative, warm

Intimate, vigorous, possessive, cheap

Dark red Graceful, serious, dignified Arrogant

As the bracket after the title of the table suggests, the course team disagreed with some of the connotations — so you may too.

The following are only suggestions for the websites; you may have better ideas.

A lively colour such as bright red, yellow or orange seems appropriate. All of these colours are active and exciting. As such, they should attract young people.

A subdued green could be used, as it would remind users of the countryside and the enjoyment they get from walking. œ Deep red would create a dignified environment, which would be appropriate for the purchase of an expensive item of this sort.


Consider the use of images in the following three cases. What additional benefits would the use of each image provide?

How could you use a picture to improve an employee record on a personnel system for a large company?

How could you use a diagram to add clarity to a screen-based control system for a car factory?

How could you use a graph or chart for a management information system providing data about absentee rates in a factory?

Images could provide the following additional benefits in the three cases.

A photograph of the employee could be put on the record. This would mean that the personnel officer could readily identify the individual if she wanted to speak to him.

A diagram of the factory floor could be included. This could include all the machines, indicating their status and highlighting any problems that have arisen. Illustrating the positions of the different machines could help the operator to solve problems. For example, if one machine has broken down and there is an operational one nearby, then this could be used instead.

A bar graph could be generated that illustrates the level of absenteeism for each month in the year. This representation would make it much easier to spot the highs and lows. This information could be used for investigating why problems arise at particular times in the year.

Notes on Review Questions for Chapter 14NONE


Look back through Chapter 14. How did Tokairo approach the process of design? List the main decisions they made.

The main decisions were made in informal meetings. Tokairo constructed both high- and low-fidelity prototypes to help communicate their ideas. They drew in ideas from other areas. In particular, the idea for the worksheet resulted from a consideration of

several existing forms, and the idea for the kiosk resulted from the designers’ familiarity with ATMs.

Tokairo decided upon the main design principles, the interaction devices, screen layout, use of colour and font. They must also have agreed on the different screens and how they relate to each other; this would have been the result of an informal conceptual design process (they probably would not have called it that).


How did Tokairo evaluate the worksheet and kiosk? Why did they choose different approaches?

The new worksheet design was evaluated with the drivers. This approach was taken because it did not seriously interrupt their working practices and provided immediate, high-quality comments. The kiosk was evaluated by Rachel, acting as a proxy user. This approach was taken because testing it on the drivers would have been difficult to organise. Involving Rachel also helped to ensure that the expertise in Tankfreight was fully exploited.


Before we start, let’s make sure that you are familiar with some of the different widgets we will be looking at. Match the widgets illustrated in Figure 4 with the following list: primary window, dialog box, menu bar, toolbar, command button, option button, check box, drop-down list box and text box.

If you are using a different version of Microsoft Windows, these widgets may look slightly different to the ones on your computer, but the differences should not be too great and the design issues that we cover in this section are just as relevant.

Figure 4 Some Windows 95 widgets

a is a menu bar, to which drop-down menus are attached. Many of these menus, in particular the File and Edit menus, are industry standard.

b is a drop-down list box, from which the user can choose the appropriate printer.

c is a check box that allows the user to indicate whether the pages should be collated.

d is a command button. Close is a standard Microsoft Windows command button usually used to close the current dialog box and, in this case, to cancel the printing operation.

e is a toolbar, which allows a range of useful operations such as printing and saving to be carried out.

f is one of three option buttons, which allow the user to specify the pages of the document to print.

g is a text box into which the user can enter the pages to be printed.

h is a dialog box. The dialog box is the rectangular area indicated. This is the print dialog box, which guides the user through printing a document.

i is a primary window. The window is the rectangular area indicated. The precise area indicated is known as the title bar. This is the main window for Microsoft Word.


1. Before we start, let’s make sure that you are familiar with some of the standard terminology used in web page design. Match the features illustrated in Figure 5 with the following list: frame, link and navigation bar.

2. What is a home page?

3. What is an interior page?

Figure 5 Different parts of a web page (taken from http://www.worcestershire.gov.uk/libraries/homepage.htm on 23/01/01)

1.

a is a frame. This is an area of the screen that can be accessed and controlled independently. In this case it is difficult to see that it is a frame because the background is the same colour as the main web page. Not all websites use frames.

b is the navigation bar (it is also a frame). It groups together links to other parts of the website. Navigation bars are sometimes located across the top of the screen. Not all websites have separate navigation bars.

c is a link. Links can be represented in a variety of ways. The traditional representation is blue underlined text. In this site, links are represented by blue underlined text and buttons.

2. The home page is the main entrance into the website. It is sometimes preceded by what is known as a splash page. This contains very basic information about the site, often in a dramatic visual form, plus a link to the home page.

3. Interior pages are those pages that you move to from the home page. Any page within a site that is not the home page (or the splash page) is an interior page.


Figure 6 contains the home page for lastminute.com, who book air flights and provide a range of other related services. How well does this page appear to satisfy the HOME-RUN principles? You will not be able to comment on all the principles, and will have to make assumptions about the rest of the site, but they provide a useful way of evaluating a page.

Figure 6 The lastminute.com home page (taken from http://www.lastminute.com/lmn/default.asp on 27/09/00)

High quality content. It can be seen from the navigation bar that this site can be used for booking flights, hotels, entertainment and a range of other things. These services would be very useful if you were going on holiday or travelling abroad with work.

Often updated. This is crucial to a site of this type. It does not indicate how often it is updated on this part of the web page. It does mention ‘our bestsellers in the last 60 minutes’, which suggests it is kept extremely up-to-date.

Minimal download time. There are some graphics, but they are quite small, so the download time should not be too much of a problem. In addition, this home page provides the users with a huge range of links, so having downloaded this page, they should be able to find the page they need without having to download too many more.

Ease of use. The page provides alternative approaches to navigation, using both the navigation bar and a variety of links. The layout of the screen is generally good, with white space separating the columns and the list items. The important words are

emphasised with a larger font. It is rather crowded, but it provides a wide range of options.

Relevant to user’s needs. This site is particularly targeted at users who want to book something at the last minute. One section has the title ‘our bestsellers … in the last 60 minutes’. This is likely to meet users’ needs, as we are in a rapidly changing society and unexpected situations and opportunities frequently arise.

Unique to the online medium. This site provides worldwide 24-hour access to up-to-date information. It also allows bookings to be made. It is difficult to see how this could be achieved so elegantly using any other medium.

Net-centric corporate culture. The website is central to the operation of lastminute.com (this is not apparent from the home page, I just happen to know this).

The lastminute.com site satisfies the HOME-RUN principles well.


Referring to Norman’s definition given above, which of the following are information appliances?

A video cassette recorder.

A pocket calculator.

A desktop PC.

A video cassette recorder is designed to carry out a particular task. It communicates information to the television and amplifier. This suggests it is an information appliance.

A calculator is designed to carry out a particular task. However, few dedicated calculators can share information with other devices, so calculators are not information appliances (although subsequent versions probably will be).

A PC is a general-purpose machine; it is not designed to carry out a particular task. Thus the PC is not an information appliance.


The following is a description of two different imaginary PDAs.

The Pen ’U Like. This includes a diary, address book, to-do list and memo pad. It has a large screen and uses handwriting recognition. It also has a small number of buttons (both physical and screen). The device can be held comfortably in one hand.

The Keys ’R Us. This has a calendar, scheduler, to do list, clock, calculator and memo pad. It has a small keyboard and small screen. It uses a clamshell design, so it is small enough to fit in your pocket when closed. When open it is a similar height to the Pen ’U Like but is wider, because of the keyboard.

Which of the two devices would you choose for the following scenarios, and why?

1. You are a travelling salesman and you need to use the PDA to store addresses and order details. The data entry must be rapid, as you need to enter the data as the client speaks. The data entry is likely to take place in the client’s office, so there will be a desk to lean upon.

2. You are a reporter on a local newspaper and you need to take notes when you visit fairs and garden parties.

1. It really depends upon the software available. If we are restricted to the software that is provided, it seems sensible to use Keys ’R Us, since the keyboard will allow the salesman to enter the data more quickly using the memo pad. However, if there is a dedicated database package for the Pen ’U Like, which only requires calling up the relevant entry and ticking a box, this would be better.

2. This is difficult, as neither PDA is ideal. Keys ’R Us is better for entering long strings of text because it has a keyboard. However, because the keys are small this could still be rather laborious. Also, it would need to be put on a hard surface, which might be a problem at a fair or garden party and the keyboard could get dirty if it is used outside too much. The Pen ’U Like would not be so suitable for entering the text. However, it would be easier to enter data without setting it down, and the device is likely to be more robust. On balance, we would use pen and paper or a dictaphone!


Figure 7 illustrates the remote control for a television and video player. The remote is connected to the television and video player via an infrared link. Consider the design of this remote in terms of the following issues.

Portability. What advantages and disadvantages are there to this device being portable? In particular, think of the environment in which the device is being used and the likely characteristics of the users. Consider each of the issues listed in the section on portability.

General purpose vs. special purpose. Is this device general or special purpose? What impact does this have upon the design? How could the design be simplified?

Figure 7 The remote control for a television and video player

Portability. The purpose of this device is that it can be operated at some distance from the television, so portability is essential. Such devices tend to be quite small, which

means they do not take up too much space on a table or chair. However, this also means that they are easy to lose (why do they make them black, which makes losing them even easier?). They can also slip between cushions on the sofa or be carried out of the room to answer the telephone. Because they are small, the buttons are also small and close together, which makes it harder for older people and young children to operate them. This is unfortunate, considering that these two groups tend to be frequent television viewers.

They tend to be quite robust as they are likely to be treated quite harshly.

There is no fragile screen.

Batteries tend to last a long time, and if they fail it is unlikely to be serious, unless you are physically disabled and unable to reach the television.

Remotes are often used in darkened rooms. Thus the layout of the buttons is important. The rewind and fast forward buttons are positioned so they reflect the movement of the tape, which is useful. Also, the power button is a distinctive shape and can be easily found at the top of the device. Some remotes have back lighting.

General purpose vs. special purpose. This remote is used to control both the television and the video recorder. This means that it is less special-purpose than it might have been. Complexity is added to the design in the form of additional buttons. One approach might have been to have two separate remotes, but this means having two to lose rather than just one! Some frequent tasks have been allocated to particular buttons. For example, one button switches the television on and off.


List the main activities that the FAST team needed to perform before an observation session with the controllers.

The team performed the following main activities before an observation session.

Writing the evaluation plan.

Creating the prototype.

Choosing the users and telling them what would be involved.

Writing the questionnaire or choosing a standard questionnaire.

Choosing some general questions for the debriefing.

Setting up the evaluation room (including any audio or video equipment, and the workload assessment tool).

Preparing for observation sessions can take a lot of time, so it is a good idea to plan early.


List the main activities that the FAST team needed to perform before they were able to inspect the user interface.

The main activities the FAST team needed to perform before they were able to inspect the user interface were the following.

Predicting the likelihood of errors. The in-house methodology already existed, so the team did not need to identify the questions it should ask about the UI. However, to be able to answer the question they would have needed to carry out a task analysis, and read the UI design literature.

Guideline review. The team would have needed to create a customised style guide (this should have been developing throughout the development lifecycle), or at least been aware of the design principles and guidelines they had attempted to apply to the UI design.


List one benefit (according to the FAST team) of each of the following: user-centred design and evaluation, questionnaires, the workload assessment tool, inspection of the UI.

The following are some of the benefits identified by the FAST team.

User-centred design and evaluation. It ensured that the controllers’ detailed domain knowledge was taken into account in the design. It also meant that the controllers were more likely to accept the new system.

Questionnaires. These gave less vocal controllers the opportunity to have an equal say.

The workload assessment tool. This produced quantitative data, which could be compared against the workload levels measured for the existing system. In this way it was possible to see whether FAST had reduced the controllers’ workload.

Inspecting the UI. This could save time by allowing them to spot obvious usability problems before investing the time and effort into setting up a user observation session.

Notes on Review Questions for Chapter 20Review Question 20.1

Given below is a list of statements that refer to the usability of a new computer system recently introduced in the local branch of a bank. Classify these statements in terms of the usability attributes of efficiency, effectiveness and satisfaction. (As an example: suppose that a customer mentioned that when he now calls the bank, the personal banker gives the required information in half the time than before the new system was introduced. In this case the customer is referring to the efficiency of the new system.)

1 The bank clerk said that she is happy with the new system, as she can attend to more customers per hour than before.

2 The complaints for incorrect statements have reduced.

3 The queuing in the bank has reduced.

4 This branch can also issue travellers cheques in foreign currencies, a facility that was not available before the system was introduced.

1 The bank clerk is expressing her satisfaction while talking about the efficiency of the system.

2 This statement implies that the system is more effective.

3 This relates to effectiveness and efficiency, resulting in satisfied customers.

4 This statement means that the system is more effective than before.

Review Question 20.2

Describe two important characteristics of the usability evaluation process that are also fundamental to user-centred design.

1 Evaluation is iterative in nature, and evaluation activities may need to be revised and repeated.

2 Design is not undertaken activity by activity - the edges blur, and there is a large amount of overlap and interaction between the activities. For example, when identifying usability defects in the data (analysis), simultaneously you are thinking of the causes for the problems (interpretation), and considering ways of overcoming the usability defects (recommendations).


Determine whether each of the following usability requirements in terms is a qualitative usability requirements or a usability metric.

1. On a website announcing a seminar, a novice user (a new web user) should take no longer than 3 minutes to submit an on-line registration form.

2. The users should be able to buy cinema tickets from a ticket-vending kiosk with no training. The procedure for buying a ticket should be self-explanatory and the user interface should be easy to use.

3. The terms and conditions of delivering items ordered on an e-shopping site should be clearly displayed to catch the user’s attention.

4. The user on an e-shopping site should be able to go through the ordering process in 3 minutes.

1 and 4 are usability metrics; 2 and 3 are qualitative usability requirements.


Classify the following usability metrics in terms of effectiveness, efficiency and satisfaction.

1. The number of errors per hour should not be more than 2.

2. The user should be able to get a query clarified from the on-line help in less than 2 minutes.

3. Number of users preferring the new system to the old one should at least be 75% of the total workforce.

1. Usability metric for effectiveness.

2. Usability metric for effectiveness.

3. Usability metric for satisfaction.


A design team is involved in designing and evaluating a ticket-booking system for a travel agency. Currently, the travel agents refer to the printed manual for information several times in a working hour. In the new system, most of the information would be provided on-line and, therefore, the number of accesses to the printed manual will be reduced.

The usability metric is ‘the number of times the travel agents refer to the printed manual for information per working hour’. The design team plans to measure this usability metric during evaluation, and have set the following levels for it.

1. With the old system a travel agent uses the printed manual 6 times in an hour.

2. The design team would like to achieve a level of 2 times per hour.

3. Ideally, the design team does not want the travel agents to refer to the paper manuals at all.

Classify the three statements in terms of the following levels: planned, best case and current.

The current level is 6 times per hour. The level of 2 times per hour is the planned level. The best case level is 0 times per hour.


List the six areas for which you make decisions about while creating an evaluation plan.

The following are the six areas for which decisions are made while creating an evaluation plan.

1. The evaluation technique.

2. The participant(s).

3. The evaluator(s).

4. Task description(s) to be simulated in the prototype.

5. The location of the evaluation session.

6. Arranging the evaluation sessions.


In Chapter 22 you learned about deciding on the tasks for your evaluation. What suggestions did it make?

Choose tasks that focus on the majority of the design issues that the design team is facing. Choose the following (Dumas and Redish, 1999).

Core, high-frequency tasks.

Tasks that are very important to the users or to the business.

Tasks that have some new design features or functionality added.

Critical tasks, even if they are not frequently used.

Tasks that you feel should be validated with the users for greater clarity and understanding of the design team.

Design features that are likely to be highlighted in marketing efforts.


A colleague is involved in evaluating the user interface design of a new model of a mobile phone. She has been asked to validate the time that the user takes in ‘sending a text message with 5 words’. The planned level of this usability metric is 90 seconds. She is conducting a user-based observation session. Should she encourage the user to think-aloud, or should she opt for retrospective discussions? Give reasons for your answer.

Since the colleague is planning to collect quantitative data for the usability metric, she should not interrupt the user in any way or encourage him to talk. So instead of recording verbal protocols, she should plan retrospective discussions with the user.


What is the purpose of conducting a pilot test before an evaluation session?

A pilot test is carried out before the actual evaluation session to ensure that all that has been planned and arranged for an evaluation session works. It is a process of evaluating the evaluation material, the planned time schedule, suitability of the task description(s), and the overall running of the evaluation session.


What materials do you need for conducting an evaluation?

You need the following materials for evaluation.

Briefings for the evaluators.

Introductory material for the participant, possibly including training and a pre-session questionnaire or interview plan.

Forms for video and audio permission if you are recording the evaluation.

Task description(s).

Forms for data collection during the session or some other method of making notes.

A post-session questionnaire or interview plan.

Forms for data analysis, data interpretation and for recording recommendations for changes.


What are the different roles of facilitator and observer?

The observer observes the users; the facilitator manages the evaluation.


List the activities involved in analysing evaluation data.

Analysing the evaluation data involves the following activities.

Collating the data.

Summarising the data.

Identifying and listing the usability defects in the data.


List the activities involved in analysing evaluation data.

The following steps are involved in the interpretation of analysed data.

Determining the causes of the usability defects identified by reviewing the summarised and analysed data.

Creating recommendations to address the usability defects.

Writing the evaluation report.


Define the term severity rating.

A severity rating is a measure given to a usability defect to indicate the criticality of its impact on the usability of the UI design.


What other heuristics/design principles are you familiar with from this textbook?

The textbook has introduced, among others, the following heuristics/design principles.

Design standards such as ISO 9241.

Design principles such as affordance, feedback and visibility, as well as simplicity, structure, consistency and tolerance.

Guidelines for the use of colour and sound in the UI.

Guidelines for GUI and web page design.

Commercial style guides, for example IBM CUA guidelines.


Name three contrasting compare elements.

The compare elements listed in Chapter 27 are as follows.

User’s personal concept of what constitutes ‘a good interface’.

Heuristics.

Design principles.

Design guidelines.

Usability standards.

Customised style guide.

Cognitive questions (as in cognitive walkthrough).


Which type of evaluation (exploratory, assessment, validation or comparison) should be conducted in each of these situations?

1. John, a user interface designer, works with a company that manufactures mobile phones. He is currently involved in re-designing the user interface design of a phone. Before, he starts with the re-design he wants to find out the usability problems with the current model.

2. Jane is responsibility for designing, evaluating and developing her Department’s Intranet. One usability metric is that the download time of any Web page on this site should be less than thirty seconds.

3. Alan works for a company that develops software for financial applications. For the contract he is currently working on, his company’s client is a bank. The bank has its data on several hardware platforms (for example, PCs, Macs, and Unix systems), and the representatives of the bank had specified in the contract at the start of the project that the new software should be portable on all these platforms. Just before shipping out the software, Alan has to evaluate it and demonstrate to the bank that this condition of the contract has been satisfied.

1. John should undertake some informal exploratory evaluations. He could do this by soliciting opinion from any of his colleagues, friends, family, etc. who use the current model of the mobile phone.

2. Jane should conduct an assessment evaluation since she has to find out how much time it would take for a page to download. So it would be a task-based quantitative assessment. For the evaluation, one of her colleagues could perform the task of downloading any web page available on the site while she records the download time of the pages using a stopwatch.

3. Alan will conduct a validation evaluation. During the evaluation, he will install the software on machines of different platforms specified by the client, which will enable him to validate whether the installation and running of the software is indeed possible on all the platforms.


Look back at Rubin’s four types of evaluation: exploratory, assessment, validation, and comparison. For each of the techniques that have been discussed decide what type of evaluation(s) you can undertake with each technique. Indicate your answers by putting a tick mark in the appropriate column(s).

Exploratory Assessment Validation Comparison

Performance Measurement

√ √

Remote EvaluationHeuristic InspectionParticipatory Heuristic EvaluationGuidelines ReviewsStandards InspectionCognitive WalkthroughPeer Reviews

This is what we came up with, although different usability professionals will have different views

about which type of evaluation you can undertake with each technique.

Exploratory Assessment Validation Comparison

Performance √ √

MeasurementRemote Evaluation √ √ √Heuristic Inspection √ √Participatory Heuristic Evaluation

√ √ √

Guidelines Reviews √ √Standards Inspection √ √Cognitive Walkthrough

√ √ √

Peer Reviews √ √ √


Why is it important to get action on your findings from evaluation?

You do not achieve a usable interface by investigating users’ needs, or by finding problems. You achieve a usable interface by meeting users’ needs and by fixing problems.


What are the four groups of techniques for communicating your findings?

Involvement and interpretation

Highlights and snapshots

Reports and recommendations

Severity scales and priorities.

These techniques are not exclusive: you can certainly choose items from the different groups to use together. One of our critical readers pointed out that he would always use severity scales and priorities as an essential attribute of any communication.


What is a stakeholder?

Stakeholders are people or groups of people in an organisation who either use the application or are affected or influenced in some way by it, so they will have a direct or indirect influence on the system requirements.


Here are some remarks made to a usability specialist by colleagues from elsewhere in an organisation. Each person is at a different level of usability maturity. Match each remark to a usability maturity level.

1. “What should I put into this evaluation plan then?”

2. “We need that plan early, as I want to make sure we’ve got time to use the results for our second iteration of the design.”

3. “I don’t have time for this user-centred stuff, I’ve got to ship this on time.”

4. “I’m going to try to draw up an evaluation plan. Can you help me, because I haven’t done one by myself before?”

3 indicates scepticism. This person needs to be convinced that a user-centred approach will get a better result.

1 indicates curiosity. This person wants to find out about this technique, and may be open to learning about other usability techniques.

4 indicates acceptance. This organisation is trying user-centred techniques, but is still learning about them and relies on a few people who are more experienced.

2 indicates partnership. The person knows about evaluation, and knows that he has probably got to have more than one iteration to get a good product.


Why might a developer’s goal to do well in his job mean that he does not accept usability findings?

The developer’s personal or career goals may conflict with a desire to do well for the users. For example, the developer may be conscious that a program has to fit within a certain amount of memory, or may want to learn a particular technology in order to include it on a list of skills. These goals may be in conflict with the different goals of ensuring that the interface works well for the users.


In Chapter 6, we quoted Tyldesley’s list of measurements of usability. Which ones are particularly appropriate for measuring time spent using an interface?

Requirements based on staff time and the degree of success in use of the system are useful in two ways.

Finding out what the targets should be is a good way of justifying investigation activities.

Finding out whether the UI is likely to cause or prevent lost time due to errors and workarounds can have a big impact on the overall success or failure of the system.

Most of the list is appropriate. My selection was as follows.

(1) Time to complete task.

(2) Percentage of task completed.

(3) Percentage of task completed per unit time (speed metric).

(4) Ratio of successes to failures.

(5) Time spent on errors.

(6) Percentage number of errors.

(8) Number of commands used.

(9) Frequency of help or documentation use.

(10) Time spent using help or documentation.

(12) Number of repetitions of failed commands.

(13) Number of runs of successes and of failures.

(14) Number of times the interface misleads the user.

(16) Number of available commands not invoked.

(19) Number of times users need to work around a problem.

(20) Number of times the user is disrupted from a work task.

(21) Number of times the user loses control of the system.


Why is it incorrect to think that ‘doing usability’ means doing testing?

Usability testing is one method of investigating users’ needs and finding problems. However, you do not achieve a usable interface by testing. You achieve a usable interface by meeting users’ needs and by fixing problems — which requires making use of the findings from your testing, and following the investigation and design techniques that we covered in the earlier chapters of this textbook.

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