Usability is how something is to use. Do not take this lightly. Consider these questions:

• How quick is it to learn?
• How efficiently are they using it?
• How memorable is it?
• How error-proof is it?
• How much do users like using it?

A failure of usability is a complete failure of the feature. If people can't or won't use a feature, it might as well not exist.

It is highly likely that your website is riddled with usability problems which are confusing, annoying and turning away your users. They might not even be consciously aware why they feel bad when they use your site, but eventually (or immediately) they will stop coming back. And they won't tell you why. These failures are hidden in your Web visitor 'bounces' and 'non-retention'.

Improving Web usability is an iterative process. The site is reviewed, the top problems are fixed, then another review, then another round of fixes. Rinse and repeat.

Usability work begins with fixing the mistakes that almost everyone makes. A site redesign for usability can often double your website's success rates. Then usability gets more scientific to address the usability issues inherent in your business using usability tests (with real people), constant testing on live audiences and fast feedback cycles.

Here are some of the techniques I usually employ for Web usability contracts:

• Heuristic evaluation
• Cognitive walkthroughs
• Card sorting
• Persona development
• Web analytics
• Brainstorming (IDEO-style)

Usually the deliverable for a Web usability evaluation is a written report detailing methods used, findings and design recommendations.