Table 2.

Usability topics and their specificity to CAT.

Topic		Participants, N=15, n (%)	CAT specific/Internet fatigue measurement
Clear and/or easy to complete		12 (80)	Concerns CAT and Internet measurement
One question per screen			CAT specific
	Advantageous	13 (87)
	Did not matter	2 (13)
Similar formulated items in two thirds (N=10) of the administrations			CAT specific
	Confusion	7 (70)
	No comment	3 (30)
Different response options, N=15			CAT specific
	Positive opinion	15 (100)
Good readability		15 (100)	Specific to Internet measurement
Good test-length		15 (100)	Concerns CAT and Internet measurement
Usefulness		6 (40)	Concerns CAT and Internet measurement
Criticism about not applicable items		3 (20)	CAT specific
Enjoyment		14 (93)	Concerns CAT and Internet measurement