Table 3.

Questionnaire serving as basis for the selection of interview questions.

Acceptance	Interactional levels
Information quality	Information transporting levels
1.How professional did you perceive the (IL)?	Main modules
2.How appropriate did you perceive the detailedness of the information in the (IL)?	Elective modules
3.How comprehensible did you perceive the Information in the (IL)?	Feedback
4.How accessible did you perceive the explanations given to in the (IL)?
Perceived usability	Information transporting levels
5.How user-friendly did you perceive the (IL)?	Main modules
6.How overseeable did you perceive the (IL)?	Elective modules
7.How appealing was the design of the (IL) to you?
Personal relevance	Information transporting levels
8.As how relevant to your personal life did you perceive the (IL)?	Main modules
9.Which part of the treatment was most relevant to your personal life? Which part of the treatment did you perceive most irrelevant to your personal life?	Elective modules feedback
10.How new was the information in the (IL) to you?
11.How good could you identify with the testimonials?
Perceived utility	All levels
12.As how helpful did you perceive the (IL)?	Main modules
13.Which insights did you develop during the treatment?	Elective modules
14.As how useful did you perceive the (IL) in your everyday life?	Feedback
15.How much did your stress improve during the treatment?	SMS coach
16.As how efficient did you perceive the treatment to reduce your stress-complaints?	Diary applications
Perceived support	All levels
17.How supported did you feel by the feedback of the eCoach?	Feedback
18.Only for Modules: As how supporting did you perceive the reminders?	Main modules
19.How comfortable were you with the degree of anonymity?
Adherence	Interactional levels
Abidance of instructions	Only compulsory levels
1.How precisely did you follow the instructions?	Main modules
2.How good could you implement the exercises in your everyday life?
Thoroughness of task-completion	Only compulsory levels
3.How thoroughly did you complete the (IL)?	Main modules
4.How often did you skip tasks in the (IL)?
Regularity of task-completion	Only compulsory levels
5.How regularly did you complete the (IL)?	Main modules
6.How regularly did you complete the homework of the (IL)?
Media utilization	Only additional levels
7.How often did you use the (IL)?	Elective modules
	SMS coach
	Diary applications

Abbreviations: IL = Interactional levels. (To capture the participants' experiences with each of the implemented multimedia options two interactional levels were assessed separately in the self-report questionnaire and later in the interview: (1) levels transporting information as the main modules, the ad elective modules and the feedback, and (Andersson et al., 2016) levels focused on knowledge transfer as the feedback, the SMS coach and the diary applications. We associated the adherence-focused feedback with both levels as it consisted of informative facets as well as of motivational facets. Some questions were exclusively applicable to the modules, as questions concerning the testimonials or the homework).