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 (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 I 2. Where can I go from here Means for navigation Navigation key Soft keys Short-cut keys Guidelines 1 Navigation Consistency is important to support learning both inside and between applications Use navigation solutions the users already know Show soft key labels Follow the standard for use of soft-keys Use standard terminology in users own language Use automatic storage and retrieval Inconsistent 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 screen Submeny on soft key Simple applications Meny on tabs and on soft keys More complex applications Some users do not perceive the tabs Tab

Molde University College INF 245 Fall 2007 OBø Alternative menus Second 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