You always wanted to know what different methods there are in usability evaluation? Then I'll give you a short overview here.

What is a usability evaluation?
It's a process that collects information about the usability of an interactive system in order to improve the interactive system (formative usability evaluation) or to evaluate the performance or value of the interactive system (summative usability evaluation).

Usability evaluations include:

Usability testing
User survey
Usability inspection
Usability evaluation can be divided into two categories, user-centered and inspection-based.

User-centered
The usability test and the user survey belong to the user-centered methods. Here I will go into more detail about the usability test. This is because it can be conducted in three forms.

First, the unmoderated form. This usability test can be performed by the user without a moderator. Therefore, it is also recommended to perform this variant first. Because of the independence of the user and the saving of the moderator, it is a cheap and fast way to get results. Equally good is that the given tasks are better and more precise, because there is no moderator on site to explain it.

The second form is the remote test. This can easily take place via an Internet connection such as Zoom or by telephone. Here it is very convenient that both parties do not have to be at the same place. Especially in Corona times, this variant was found to be very good, as there was no risk of infection at all. Of course, this variant is a bit more expensive than the unmoderated one, because there is a moderator.

Last but not least, the third form, perform the test in presence. This variant is very expensive, because a moderator must be on site, a usability laboratory must be available and the many other costs of the conditions. For this reason, this variant is only used when special conditions prevail.

Inspection based
Cognitive Walkthrough

In a cognitive walkthrough, a usability expert evaluates the interactive system from the user's point of view by putting himself in the role of a user. In doing so, he performs concrete tasks with the interactive system and checks the fulfillment of the usability criteria from the perspective of a persona. This type of evaluation is also called persona-based usability inspection.

Heuristic Evaluation

A heuristic evaluation is a usability inspection method in which evaluators compare an interactive system against a list of heuristics and determine where the interactive system fails to follow them.

If you want to learn more about heuristics, feel free to check out our articles "Heuristics and Interaction Principles - A Comparison" and "The 10 Heuristics According to Norman Nielsen".

Expert Review/Review

Expert-based evaluation is a combination of Cognitive Walkthrough and Heuristic Evaluation. I have already explained the two methods above. But when is expert review used? It can be applied in the concept phase already with the first scribbles or wireframes. Another possibility is during the implementation of the interactive system or shortly before the launch of the interactive system. A quality control, so to speak, before the interactive system is actually published. The last possibility is that the interactive system has already been put into operation and through the expert review weak points could be identified in order to fix them directly during a relaunch.

Source: UQXB Curriculum CPUX-F 2020, UQXB Curriculum CPUX-UT 2020