Motivation
For most projects, usability is the highest priority non-functional attribute. To most people, the UI is the application. It makes or breaks the application.
Usability
Components:
- Learnability
- Efficiency
- Error Rate
- User Retention
- Satisfaction
- Usability
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A measure of how easy a system it is to use. In this context, usability is a non-functional requirement (or quality attribute).
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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]
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A term that describes the study of ease of use, including methods and techniques for improving human-computer interaction.
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Factors that Determine Software Usability
- Learnability: how easy is it to use for the first time?
- familiarity
- consistency
- predictability
- simplicity
- Efficiency: once users learn how to accomplish a task, how easy is it to perform?
- Memorability: how easy is it to use the application after not using it for a long period of time?
- Low Error Rate: few errors, easy to recover from errors that are made
- Confidence and Satisfaction: how pleasant or enjoyable is the application to use?