What is Usability?
Usability refers to the ease with which a User Interface can be used by its intended audience to achieve defined goals. Usability incorporates many factors: design, functionality, structure, information architecture, and more.
Usability looks at 5 components (usability.gov):
- Ease of learning: How fast can a user who has never seen the user interface before learn it sufficiently well to accomplish basic tasks?
- Efficiency of use: Once an experienced user has learned to use the system, how fast can he or she accomplish tasks?
- Memorability: If a user has used the system before, can he or she remember enough to use it effectively the next time or does the user have to start over again learning everything?
- Error frequency and severity: How often do users make errors while using the system, how serious are these errors, and how do users recover from these errors?
- Satisfaction: How much does the user like using the system?
What are the Benefits?
- increase productivity and customer satisfaction
- increase sales and revenues
- reduce development time and costs and maintenance costs
- decrease training and support costs
Practical Usability Guidelines
From Userfocus’ 247 web usability guidelines page:
- Home page usability
- Task orientation
- Navigation and IA
- Forms and data entry
- Trust and credibility
- Writing and content quality
- Page layout and visual design
- Search usability
- Help, feedback and error tolerance