Expert Review

Although an expert review can highlight potential issues for users, the experts who conduct the review are not your users. User experience is best understood by observing users engaged with your interface. When you conduct an expert review before usability testing, you have the chance to clean up the interface of identified issues and then conduct user testing to see what else you can learn from your users.

There are no clear distinctions between these two ways of characterizing an inspection. Some practitioners use “expert review” to mean a review by a single expert and “heuristic evaluation” to mean a review by several experts. Other practitioners use heuristic evaluation to mean a review using a clearly defined set of heuristics, such as those by Nielsen. In contract, these practitioners would call the inspection an expert review when the heuristics are internalized through familiarity and practice.

We use the terms interchangeably to mean the same thing, and we adopt the methodology best suited to the client’s needs with regard to the choice of heuristics (or not) and the number of reviewers.

Jakob Nielsen, who is credited with combining the practices of a small set of evaluators for a heuristic evaluation and a small set of users for a usability test into a method called “discount” usability engineering, found that the maximum cost-benefit ratio for heuristic evaluation is achieved with 3-5 evaluators.

That’s a lot of experts! Most practitioners use fewer experts for reviews, with some doing reviews by a single expert. We advocate using 2-3 reviewers for effective results.

Usability testing provides feedback from users while they engage in typical tasks. Heuristic evaluation provides feedback from usability experts (who may or may not be domain experts), based on anticipated issues users will face.

Both tools are widely used, and both produce useful findings. So, one is not better than the other. However, they do produce different kinds of findings.