Table 2.

Additional resources.

Assessment approach	References and resources
Cognitive or task walkthrough	[14,29,39,40,49,50]
Graphical evaluation	[30,31,42,43]
Post hoc questionnaires and interviewsa	[23,32,37,44,45,51]
Physical performance evaluation	[33]
User interface evaluation	[14,34]
Heuristic evaluation	[14,21,36,52]
Other	[53,54]

^aThis represents a sample of many that can be employed, depending on what usability concept is to be measured.