Table 5.

Results from the process evaluation interviews on the main theme “feasibility”.

Theme	Subtheme	Quote
Feasibility—content	General user experience	“There were some things that weren't right. But other than that, it was good.” (Girl 3, grade 9, vocational track)
	Humor	“His answers were pretty funny” (Girl 1, grade 9, vocational track)
	English language use	Interviewer: “what did you dislike about the chatbot?” Adolescent: “When you said something, it was like this when you said ‘thank you' [in Dutch]. I thought it was like this, that he started in English.” (Girl 3, grade 9, vocational track)
	Too redundant responses	“After my nephew's question of 'I'm sitting too much', the chatbot sent a little too many messages. I would send that in one message. Not so much in different messages. Those notifications came in all the time. So one message that would be enough I think.” (Girl 1, grade 9, vocational track)
Feasibility—design	Nice design	Interviewer: “if you just look at how the chatbot looked in your app. What did you think of the view?” Adolescent: “I liked that. Also nice that you can change the background.” (Girl 7, grade 7, vocational track)
	Settings page was not visible enough	“Nah I didn't do that. I see this just now…whoops” (Boy 2, third year, general academic track)
Feasibility—questions	Small talk	“I tested the chatbot, I asked if it could calculate something, but it didn't work.” (Girl 8, grade 7, general academic track)
Feasibility—answers	Answers were not always accurate	“Erm, I used it once. The first day I asked if I had to keep the Fitbit on at night because I didn't know. Erm, it was a bit weird but erm, mainly because I don't think the answers were on point yet because I got some really weird answers. I got links to videos that helped me fall asleep better.” (Girl 4, grade 9, vocational track)
	Drop-out in case of wrong or strange answers	“Um, I've only used the chatbot twice or so. I had asked something about 'how could you earn coins' [i.e., part of the app] and it gave an answer that was not clear. And then I thought well, I don't need to use it.” (Girl 5, grade 9, vocational track)
	Immediate response	“And that he answers so quickly. You have sent a message and 2 seconds later you have your answer back already. That's nice, that you don't have to wait that long.” (Girl 1, grade 9, vocational track)
	Referral to website	“I thought it was good. I used the little robot. I wrote something down and then suddenly I was sent to a website. There I could see what I wanted to know.” (Boy 3, grade 9, vocational track)
	Length of responses	“Rather short answers than long texts. Two lines is enough” (Boy 2, grade 9, general academic track)