Usability

Usability has been described by many people in very different ways. However, it is an attribute that assesses how easy your site is to use.

Usability can be broken down into five key areas:

• Ease of learning: How easy do visitors find your site to use the first time they visit it.
  
• Functionality: Once they have learnt how your site works how quickly do they get used to performing basic tasks.
• Memorability: When users come back to the site how long does it take them to re-learn what they learnt before?
• Problems: How many errors do people make on the site and he easily is it to recover from these errors. This is extremely important when considering forms.
• Satisfaction: How delighted are they with the layout and functionality of your site?

There are many other important quality attributes. A key one is utility, which refers to the design's functionality: Does it do what users need? Usability and utility are equally important: It matters little that something is easy if it's not what you want. It's also no good if the system can hypothetically do what you want, but you can't make it happen because the user interface is too difficult. To study a design's utility, you can use the same user research methods that improve usability.