What is Usability

• 11.12.2007

Designing a site that will be usable is mainly down to common sense:

• stick with conventions,
• give links to help, or further information when necessary
• clearly direct users to what they want
• make it easy to find products/information

Steve Krug got it right when in his book when he said in answer to the question ” what’s the most important thing to make sure my web site is easy to use” - “DON’T MAKE ME THINK!”.

Usability testing is an excellent thing to do and is best started from the wire frame stage, but not everybody has the budget to cover this extra expense, although it can save money in the long run by identifying any usability issues at an early stage when it’s quick & easy to rectify.

Jakob Neilson says this about usability:

Usability is a quality attribute that assesses how easy user interfaces are to use.

The word “usability” also refers to methods for improving ease-of-use during the design process.

• Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
• Efficiency: Once users have learned the design, how quickly can they perform tasks?
• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
• Satisfaction: How pleasant is it to use the design?

Usability considerations

Usability includes considerations such as:

• Can users easily accomplish their intended tasks? For example, can users accomplish intended tasks at their intended speed?
• How much training do users need?
• What documentation or other supporting materials are available to help the user? Can users find the solutions they seek in these materials?
• What and how many errors do users make when interacting with the product?
• Can the user recover from errors? What do users have to do to recover from errors? Does the product help users recover from errors? For example, does software present comprehensible, informative, non-threatening error messages?
• Are there provisions for meeting the special needs of users with disabilities? (accessibility)

Examples of ways to find answers to these and other questions are: user-focused requirements analysis, building user profiles, and usability testing.

Further reading on usability

The most straightforward, easy to understand usability expert has to be Steve Krug & his book - ‘Don’t Make Me Think‘ is a must have. There are many interviews with him on the web & a sample chapter from his book can be found on his ‘Advanced Common Sense’ site.

Useful Links

Jakob Neilson’s Alertbox is essential reading for keeping up to date with usability issues

Recommended reading