Internet users primarily visit Web sites seeking information of one kind or another — news, advice, product details, research data. Poor navigation or a confusing interface will frustrate the user in his or her quest for information, and it is easy for a frustrated user to abandon the unsuccessful search and surf off to another site. Even on a site designed for entertainment or shopping, usability problems can translate into lost visitors.
Web usability expert Jakob Nielsen [http://www.useit.com] advocates heuristic evaluation as an affordable way to produce a usable Web site. Originally developed as a technique for testing and improving software interfaces, heuristic evaluation tests a Web site for its adherence to certain heuristics, or accepted standards for usable design.
In heuristic evaluation, several evaluators will work with an interface, comparing it to a set of heuristics. Then the designers will aggregate the findings of all evaluators and use the findings to redesign the site for greater usability. The process is iterative, in that the procedure will be repeated multiple times to achieve ever greater usability.
Nielsen and consultant Keith Instone [http://www.usableweb.com] recommend the following 10 heuristics as key to Web site usability:
1. Visibility of system status
Keep users informed of where they are and what is going on. Make links clear.
2. Match between the system and the real world
Use familiar language rather than insider jargon. Organize information in a natural and logical way.
3. User control and freedom
Provide “emergency exits,” such as a link to your Home page on every page. Beware of multimedia “gizmos” that can confuse the user.
4. Consistency and standards
Make your site consistent in wording and graphic conventions, headers and links. Don’t make the user guess what something means. Use standard HTML. Follow Web standards for such elements as link colors.
5. Error prevention
Design your Web site to prevent errors. Poor or non-standard implementation of advanced technologies can cause errors that discourage and drive off users.
6. Recognition rather than recall
Make instructions easy to find. Don’t make the user remember information from one page to the next. Make sure the user always knows where he or she is on the Web site. Make sure links and image maps are clear.
7. Flexibility and efficiency of use
Design for both the novice and expert user. Provide “accelerators” so the experienced user can work more quickly with the Web site. Especially important: Make sure all pages are easily bookmarked and linked to by outside sites. Assign permanent URLs for all pages and keep them available.
8. Aesthetic and minimalist design
Avoid unnecessary page elements that can distract, confuse and obscure the most important information or navigation mechanisms. Offer “progressive levels of detail,” providing general information on top and the option to drill down for more details.
9. Help users recognize, diagnose and recover from errors
Express error messages in plain language and offer solutions to the problem. For example, rather than giving the user the standard “404 File Not Found” message, create your own branded error page with links to the site’s Home page or main content areas.
10. Help and documentation
Make help easily available and relevant to the task at hand. Make help documentation well-integrated with the pages of the site, either right on the page or through easy-to-find links.