What is Usability?
Usability assesses how easy it is for users to perform functions in documents and websites. Through detailed research and audience models, designers and writers are able to craft documents and processes that provide functionality to information and tasks.
Why is Usability Important?
If a website is difficult to use, people leave and find another website. If the homepage doesn’t clearly indicate what a company offers, or what users can do on the site, people leave. If users get lost when attempting to locate information they need, they leave. If a website is hard to read of doesn’t answer the questions they are looking for they leave. There is no point in developing a website if no one stays long enough to get the information on it.
Quality Components of Usability
Jakob Nielsen defines usability through 5 quality components:
- 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 on 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?
Other quality attributes of usability include utility, and usefulness. Utility refers to the design’s ability to function; does it provide the features the user needs? Usefulness refers to the ability to perform tasks easily and proficiently. Nielsen focuses on placing the customers’ needs at the center of the design strategy.
The Birth of Modern Usability
Jeff Suaro provides a detailed timeline on the history of Usability. Modern Usability began in 1988 when John Whiteside at Digital Equipment Corporation and John Bennet at IBM published a number of white-paper articles on the topic of
usability engineering, which stressed early goal-setting, prototyping and iterative evaluation.
Joe Dumas, one of the godfathers of usability attributes these papers and this period as the birth of usability as a profession.
Important Usability Texts
In 1999, Jakob Nielsen published Designing Web Usability that outlines the problems and solutions associated with poor design.
In 2000, Steve Krug published Don’t Make Me Think, which brings usability testing to the masses using a simplified version of usability methods.
In 2008, Tom Tullis and Bill Albert publish Measuring the User Experience, dedicated to measuring usability in a quantitative way that had become increasingly qualitative.