Molde University College INF 245 Fall 2007 OBø

Mobile Application Usability

INF245 Mobile Applications

Ola Bø

Molde University College INF 245 Fall 2007 OBø

Based on

Series 60 Developer, Platform 2.0: Usability Guidelines for Enterprise Applications (Nokia)

Molde University College INF 245 Fall 2007 OBø

Usability

Depends on many factors in addition to the product

Usability is the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use

ISO 9241-11(1998)

Molde University College INF 245 Fall 2007 OBø

Three principles for designing usable applications

1. Know the user and the context. Then you can prioritize functionality and user dialog

2. Test with real users – early and several taimes

3. Choose simplicity.

Molde University College INF 245 Fall 2007 OBø

What do we gain by improving usability?

Effects obtained by pursuing usability

Some usability improvements are easy to obtain-dropped functionality-changed terminology

Molde University College INF 245 Fall 2007 OBø

Usability in application development

Traditional system development Starts by specifying

requirements in cooperation with the users

The users will not see the system before it is completed

When the system is completed it is too late to make changes

Results in most cases in a product with low usability

Molde University College INF 245 Fall 2007 OBø

Involving the users and other stakeholders.

By consulting the users several times in the development process and adjusting requirements a better product can be made

Early involvment using paper prototyping

Several personell categories participate

Molde University College INF 245 Fall 2007 OBø

Checklists

Usability can also be improved using checklists

Molde University College INF 245 Fall 2007 OBø

Main problem for mobile applications: Too much time is used for navigations

Each screen must show:1. Where am I2. Where can I go from

here Means for navigation

Navigation key Soft keys Short-cut keys

Guidelines 1Navigation

Consistency is important to support learningboth inside and between applicationsUse navigation solutions the users already knowShow soft key labelsFollow the standard for use of soft-keysUse standard terminology in users own languageUse automatic storage and retrievalInconsistent soft key labels is the often the main usability problem

Molde University College INF 245 Fall 2007 OBø

Guidelines 2 The Main Menu

Core functionality should be easily accessible

Different menu solutions are used in existing applications

Menu only using soft key Usable for simple applications

Custom menus pros and cons?

Molde University College INF 245 Fall 2007 OBø

Alternative menus

Menu on screenSubmeny on soft keySimple applications

Meny on tabs and on soft keysMore complex applicationsSome users do not perceive the tabs

Tab

Molde University College INF 245 Fall 2007 OBø

Alternative menusSecond level tabs

Major applications with much information

Icons should only be used if their meaning

is obvious!??

What is available using the navigation key should also be available using the menus

Molde University College INF 245 Fall 2007 OBø

Option menus

Use consistent terms Most used functionality first

Why? What functionality is most used

Logical order Group related choices into sub menus Avoid scrolling in sub menus Only show available choices

Why?

Molde University College INF 245 Fall 2007 OBø

Action

Feedback should always be given Should react within 0,1s

If the action takes more time: 0,5-2 s tell user something is happening More than 2 s: indicate how much time remains to

complete the operation using a progress indicator

Molde University College INF 245 Fall 2007 OBø

Information input As little as possible, as simple as possible

How do you obtain this? A good default value Only necessary input Reduced quantity Abbreviations Cut and paste Selection better than writing, also speaking is. Changing numerical input using navigation key Formatting help

Sound and picture is an alternative Respect the users’ work

Molde University College INF 245 Fall 2007 OBø

Information Output

Chunking and order Text presentation

Fonts and contrast Graphics

Visibility Icons

Color Consistency

Sound Never solely Volume control and stop

Errors Prevention and tolerance Undo Confirmation

NB! different keys Help

Options-menu Context sensitive

Molde University College INF 245 Fall 2007 OBø

Communication with servers

Coverage problem handling The application should be robust in case of lost connection What does that mean?

Synchronization handling automatic vs. manual legal liability?

Use of words End, Close, shut down, Start, Open, Log in Where are the possible misunderstandings here? Status indication – Result indication

Molde University College INF 245 Fall 2007 OBø

Security and usability

Why may security and usability be conflicting?

How to ensure Safer log on Less frequent log on Less handling of sensitive information Safer handling of sensitive information

Molde University College INF 245 Fall 2007 OBø

Exercise