Usability evaluation and testing introduction
We test to see whether your site or application meets usability heuristics, and whether it is useful to users in the real-world context. (Also see Introduction to Usability).
We also check that the site or application complies with standards and guidelines (eg. accessibility, GUI standards, web standards, etc).
"Once a system is in development, correcting a problem costs 10 times as much as fixing the same problem in design. If the system has been released, it costs 100 times as much, relative to fixing in design."
- Gilb, Principles of Software Engineering Management, 1988
What it does for you
Usability testing lets us uncover where people are having problems using the site or application. If you test your site or application early, you can fix any major usability flaws before it’s built. This can save you an enormous amount of cost and time – up to 90% of your development costs – and prevent you from exposing your customers to a user-unfriendly system.
(See our fact sheet on findings report, which shows each issue, prioritised by severity and impact. We can also include recommendations for how to go about fixing the problems.
Sometimes these are very specific (eg. “highlight the currently-chosen section in the left menu bar to improve orientation”), and other times they’re more general (eg. “redesign the menu structure so that it follows the users’ task more closely”).
How we do it
Expert review
It’s possible to do usability testing without users: this is called an expert review. This method relies on our expertise, experience and knowledge of the heuristics to predict where users are most likely to encounter problems.
It’s a lower-budget way to uncover issues, but doesn’t uncover as much powerful detail as testing with users.
Field studies
By observing and interviewing users in the context where the site or application will be used, we can understand the context and real-life nature of the tasks it supports. Field studies are one of the most powerful tools we have to ensure that we are solving the right design problems for your users.
(Other terms for this activity are ‘contextual enquiries’ and ‘workplace interviews’). More about field studies.
Testing with users
It's more effective to test with users, because each set of users reacts a bit differently in each new context.
For testing, we use a representative sample of users to run through real tasks. We observe what they do and ask questions to find out issues about how they work, and what is going right and wrong with the current design.
This testing isn’t intended to produce a statistically valid result. Instead it’s qualitative – it lets us find out what the range of problems is, and leads us in the right direction for a redesign.
Sometimes this takes place on site (eg. in an office, people's homes) and sometimes at your premises, or ours.
We often record the proceedings on video (depending on the situation), so that it can be referred to later, and you can observe the sessions from another room.
We can do open-ended exploration, where the user chooses their task and which screens they’ll look at; or we can do scenario-based testing, where the user is asked to imagine that they are a particular user solving a particular problem.
Questionnaires
Questionnaires can also be helpful, and are administered either at the end of a usability test or as a stand-alone exercise.
