Comparison of usability evaluation methods

Usability testing methods aim to evaluate the ease of use of a software product by its users. As existing methods are subjective and open to interpretation, scholars have been studying the efficacy of each method
and their adequacy to different subjects, comparing which one may be the most appropriate in fields like e-learning,
e-commerce,
or mobile applications.

Evaluation Method	Evaluation Method Type	Applicable Stages	Description	Advantages	Disadvantages
Think-aloud protocol	Testing	Design, coding, testing and release of application	Participants in testing express their thoughts on the application while executing set tasks	Less expensive Results are close to what is experienced by users	The Environment is not natural to the user
Remote Usability testing	Testing	Design, coding, testing and release of application	The experimenter does not directly observe the users while they use the application though activity may be recorded for subsequent viewing	Efficiency, effectiveness and satisfaction, the three usability issues, are covered	Additional Software is necessary to observe the participants from a distance
Focus groups	Inquiry	Testing and release of application	A moderator guides a discussion with a group of users of the application	If done before prototypes are developed, can save money Produces a lot of useful ideas from the users themselves Can improve customer relations	The environment is not natural to the user and may provide inaccurate results. The data collected tends to have low validity due to the unstructured nature of the discussion
Interviews	Inquiry	Design, coding, testing and release of application	The users are interviewed to find out about their experience and expectations	Good at obtaining detailed information Few participants are needed Can improve customer relations	Can not be conducted remotely Does not address the usability issue of efficiency
Cognitive walkthrough	Inspection	Design, coding, testing and release of application	A team of evaluators walk through the application discussing usability issues through the use of a paper prototype or a working prototype	Good at refining requirements does not require a fully functional prototype	Does not address user satisfaction or efficiency The designer may not behave as the average user when using the application
Pluralistic walkthrough	Inspection	Design	A team of users, usability engineers and product developers review the usability of the paper prototype of the application	Usability issues are resolved faster Greater number of usability problems can be found at one time	Does not address the usability issue of efficiency