iFocus - Maximise usability

Web site usability testing. It’s a step most people think of as a luxury, but it’s more like a check-up. You can pay a little up front for some preventative medicine, or find yourself at the end with a very expensive headache.

What is usability testing?

Usability testing evaluates the ease with which the users of your web site can interpret its design and use it to find the information they want. Do they understand the terminology you’ve used to organise the information? Can they recognise that the icons you’ve used are links?

It also determines the preference of the target audience in terms of design, look and feel. Are they intimidated by an extremely rigid, corporate feel? Do they respond better to something more casual?

Usability testing is often treated as an afterthought. It’s performed at the end of the implementation, if there’s time and budget left over. Or, it may be used as a diagnostic tool to evaluate a problem that has been detected in an existing web site.

Performing usability testing in this way is not cost effective. It means that the necessary changes are identified when they are most expensive to fix: after the implementation.

How it should be done

If a version of the site currently exists, usability testing should be performed prior to the design phase of the next version. This helps to identify any problems with the current design that need to be resolved by the new design.

Once an interface has been designed, even in the form of a wireframe, a usability test should be performed to identify any problems with the new design.

Small and frequent tests should continue throughout the development cycle, from design through to implementation, to detect and resolve any problems introduced.

Cost-effective testing

Wireframe user testing is the most basic method of evaluating web site usability. Using a wireframe design displayed on screen in a diagramming program such as Microsoft Visio, the web site’s design is presented to people who are likely to comprise its target audience. The participants are then asked to perform specific common tasks using the wireframe, such as finding a particular piece of information or purchasing a product. The researcher watches and listens to the participants and records where they succeed in using the site as intended and where they fail.

By using small, frequent tests to build from the wireframe prototype up to a fully functional web site, no time is wasted in building functionality that doesn’t work or is unnessecary. Critical flaws are excluded from later, more costly phases of the implementation.

According to web site usability expert Jakob Nielsen, 10% of the design budget needs to be alloacated to usability. He also says that an effective usability test can be performed with as few as five people. Each person you test will tell you something new about the design, but that person will also do a lot of the same things the as the previous person. This diminishing return means that just a handful of people are sufficient to return useful results.

How usability saves money

Usability testing saves money by limiting the design to include only the functionality that users really need. Iterative testing systematically eliminates unnecessary functionality from the design.

Design mistakes are detected and corrected early. Changes are not delayed until further down the development path, when they will affect other parts of the site and be more costly to fix.

The resulting design will endure longer because it is designed specifically to meet user requirements.

iFocus and usability

iFocus usability analysis projects have included:

surveys, to measure the level of customer satisfaction with an existing web site
taxonomy and classification research, to measure the utility of a web site’s information architecture
task based usability testing of a new web site design, to measure the effectiveness of the overall design
focus groups.

IRISTM (Integrated Review of Internet SystemsTM) is an iFocus methodology that analyses the usability of online systems, such as web sites, intranets and extranets. As part of a comprehensive report on the efficacy of the system, the IRISTM provides feedback on the architecture of the web site’s content and its impact on usability.

Research clients have included QR (customer satisfaction and usability), the eTenders web site for the Victorian government (customer satisfaction), the City of Melbourne (taxonomy and usability), and the Victorian Department of Innovation, Industry and Regional Development (taxonomy and usability).

Some final quick tips

Be consistent—use the same visual cues throughout the web site.
Leave a trail—navigation should clearly show where you’ve been and where you’re going.
Use plain English—no jargon or “corporatese”.
Ask the user what they think—web sites must be designed from the perspective of the target user, not the organisation.

References

For more information

For more information, contact iFocus.