According to statistics published by the Online Marketing Institute a web site with poor usability isn't too popular with visitors:

• 85% abandon a site due to poor design
• 83% leave because it takes too many clicks to get what they want
• 62% gave up looking for an item while shopping online
• 40% never return to a site because the content was hard to use
• 50% of sales are lost because visitors can't find content

Unfortunately, most people go on without realizing the effect that the way their site is laid out could be the reason they are unsuccessful; they don't understand how important usability really is.

What is usability and why is it important?

Usability can be simply defined as making something, in this case a web site, easy to use. This means the content is easy to read, visitors can easily navigate the site, pages aren't broken and visitors can accomplish basic tasks. Jakob Nielsen, co-founder of the Nielsen Norman Group, explains why this is so important. "On the Web, usability is a necessary condition for survival. If a website is difficult to use, people leave. If the homepage fails to clearly state what a company offers and what users can do on the site, people leave. If users get lost on a website, they leave. If a website's information is hard to read or doesn't answer users' key questions, they leave. Note a pattern here? There's no such thing as a user reading a website manual or otherwise spending much time trying to figure out an interface. There are plenty of other websites available; leaving is the first line of defense when users encounter a difficulty."

The usability audit

Nielsen suggests that 10 percent of a project's budget be spent on usability. For a new site, this means having an expert weigh in on certain aspects of the design and layout of the site. For an existing web site, this usually means the site will undergo a usability audit to find out where things are broken and how they can be fixed. The usability audit is the process of auditing the web site's interface from the viewpoint of a user to identify any errors in the design as well as their causes. The audit will also provide recommendations for fixing these problems. For web sites, the usability audit usually breaks down into three main categories:

This portion of the audit looks for anything that might prevent a user from accessing any section of the site. Some of the things that an audit might look for are:

• Does the site take too long to load?
• Is the text to background contrast adequate for most people's eyes?
• Is the font easy to read (it's not too small, the spacing is appropriate, it's clear).
• Images load and all images contain appropriate ALT text.
• Flash content is kept to a minimum.
• The site can be viewed on different devices and screen resolutions.

This describes how users are able to move throughout the site and find the information they came looking for. Some aspects that an audit may address are:

• The menu is easily identifiable.
• Navigation labels are clear.
• Logos return the user to the homepage when clicked.
• Links are consistent and work.
• Links are easy to identify.
• Content is searchable.

Content is why people come to a site in the first place so if this part of the site is broken, people will leave. Usability audits will usually address the following content issues:

• Important content is above the fold.
• Headings are clear and descriptive.
• Emphasis and text decoration is used sparingly.
• Images compliment the text.
• Copy is well written at an appropriate level for the audience.
• Page titles and URLs are explanatory.

An outside party should do conducting a usability audit since the designer or site owner is familiar enough with the web site to miss certain flaws that users could find discouraging. Once the results of the audit are back, take the time to plan how you will address each concern. While there will likely be recommendations on what steps to take, it is important to prioritize which elements need to be addressed first and which ones can wait until later. Once the priorities are identified, get to work on fixing problem areas.