Jaspers, M.W.M. 2009. “A Comparison of Usability Methods for Testing Interactive Health Technologies: Methodological aspects and Empirical Evidence.” International Journal of Medical Informatics 78 (2009): 340-353.
Jaspers identifies two major types of expert evaluation: heuristic evaluation and cognitive walkthrough. Heuristic evaluation is a relatively efficient usability evaluation method with a high benefit-cost ratio, but requires high skills and usability experience of the evaluators to produce reliable results. Heuristic evaluation is widely used since it generally requires less resource than testing with users. But it is fundamentally different from usability testing. The cognitive walkthrough is a more structured approach than the heuristic evaluation with a stronger focus on the learnability of a computer application. The limitation is the required level of detail of task and user background descriptions for an adequate application of the latest version of the technique.
User-based testing methods include user performance measurements, log-file and keystroke analyses, cognitive workload assessments, satisfaction questionnaires, interviews and participatory evaluation. Among these methods, the participatory evaluation can give the clearest indication as why a certain interface aspect poses a problem to a user or how to improve the interface. For example, through talking or thinking aloud or in a retrospective interview, the participants can reveal the underlying causes for system usability problems encountered and participatory evaluation thus has more reliability. Scholars such as Jaspers regard “think aloud” as a very direct method to gain deep insight in the problems end users encounter in interaction with a system (340). Many also suggest that test participants need to be diverse but representative of the envisioned users.
Heurstic evaluation have a higher benefit-cost ratio, but it require higher skill set in usability experience. The cognitive walkthrough is more structure than Heurstic but need to have high level detail of task and background. And the think aloud technic is great way to get in-depth detail on problem which user are facing.
Continue discovery, research and hand on experience in this area of technology is a must.