What is Usability

Briefly, usability is about designing a website that is easy to use so that it will appeal to as many visitors as possible.

The International Standards Organization (ISO 9241) defines usability as:

System usability comprises 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, where:

Effectiveness measures the accuracy and completeness with which users achieve specified goals;

Efficiency measures the resources expended in relation to the accuracy and completeness with which users achieve goals;

Satisfaction measures the freedom from discomfort, and positive attitudes towards the use of the product.

I’ve simplified this a bit. My definition: Easy to complete tasks makes users happy.

Your website should be able to be used by as many visitors as possible without confusion. If visitors aren’t able to find what they are looking for I can guarantee they will leave and head to one of your competitors.

So where should you start? Find where your problem areas are on your site, and fix them.

Easy to complete tasks makes users happy.

Craig Kistler, Small Farm Design

5 Factors of Usability

Learnability. How quickly can a new visitor learn the user interface to accomplish basic tasks? Is the design of the site intuitive?

Efficiency. How quickly can users perform tasks, find products etc?

Memorability. Can a returning visitor remember how to effectively use your site or application or are they forced to relearn everything from the beginning?

Errors & Error Frequency. How often does a visitor make errors while using your website? How serious are these errors? Why are they making them and can they easily recover from these mistakes?

Satisfaction. After completing their task does the user have a good feeling about your company?

Focusing on these five points will give you a good start on fixing basic usability issues.

Designing with a focus on usability will enable you to create a website that matches your visitors expectations enabling them to complete their tasks with great satisfaction. The return on designing with an eye on usability is massive.