Table 3.

Task usability results: effectiveness, efficiency (task observations) and satisfaction (task interviews)

Task/feature	N	Effectiveness	n	Efficiency	n	Satisfaction	n
Task 1	20	Effective	19	Efficient	11	Satisfied	17
Register				Partly efficient	8	Neither satisf./dissatisf.	2
				Partly inefficient	0	Dissatisfied	1
				Inefficient	1
Task 2	12	Effective	10	Efficient	3	Satisfied	3
Ask a question				Partly efficient	5	Neither satisf./dissatisf.	7
				Partly inefficient	2	Dissatisfied	2
				Inefficient	2
Task 3	12	Effective	11	Efficient	5	Satisfied	9
Search answer by words in search function				Partly efficient	4	Neither satisf./dissatisf.	1
				Partly inefficient	2	Dissatisfied	2
				Inefficient	1
Task 4	20	Effective	19	Efficient	3	Satisfied	7
Search answer by category				Partly efficient	5	Neither satisf./dissatisf.	8
				Partly inefficient	11	Dissatisfied	5
				Inefficient	1
Task 5	12	Effective	11	Efficient	3	Satisfied	7
Technical help from moderator or help function				Partly efficient	4	Neither satisf./dissatisf.	3
				Partly inefficient	4	Dissatisfied	2
				Inefficient	1
Task 6	8	Effective	8	Efficient	3	Satisfied	3
Register as expert				Partly efficient	1	Neither satisf./dissatisf.	2
				Partly inefficient	4	Dissatisfied	3
				Inefficient	0
Task 7	8	Effective	8	Efficient	6	Satisfied	6
Answer a question				Partly efficient	2	Neither satisf./dissatisf.	1
				Partly inefficient	0	Dissatisfied	1
				Inefficient	0
Task 8	8	Effective	8	Efficient	5	Satisfied	6
Add a supplementary answer				Partly efficient	3	Neither satisf./dissatisf.	2
				Partly inefficient	0	Dissatisfied	0
				Inefficient	0

Participants (N = 20) are questioners from the working population (N = 12) and experts (N = 8). Questioners executed Tasks 1, 2, 3, 4 and 5. Experts executed Tasks 1, 4, 6, 7 and 8.