Table 5.

Number of usability problems of usability categories according to severity level.

Usability category	Severity category				Total (n=400), n (%)
	Minor usability problems (n=186), n (%)	Serious usability problems (n=147), n (%)	Critical usability problems (n=67), n (%)
Basic system performance	32 (17.2)	10 (6.8)	14 (20.9)	56 (14)
Task-technology fit	16 (8.6)	7 (4.8)	5 (7.5)	28 (7)
Accessibility	2 (1.1)	5 (3.4)	1 (1.5)	8 (2)
Interface design	51 (27.4)	38 (25.9)	7 (10.4)	96 (24)
Navigation and structure	12 (6.4)	18 (12.2)	12 (17.9)	42 (10.5)
Information and terminology	13 (6.9)	13 (8.8)	1 (1.5)	27 (6.7)
Guidance and support	56 (30.1)	55 (37.4)	25 (37.3)	136 (34)
Satisfaction	4 (2.1)	1 (0.7)	2 (3)	7 (1.7)