So I want to do a survey with seven question-groups (participants should answer the same questions for seven different videos).
As one group takes pretty long to answer, I want every participant to only answer four of the groups. This should happen randomized, so that in the end I have about the same amount of data for every group.
As I found out so far, this "X out of Y"-problem is easy solvable as long as it is about questions in the same question-group (as shown
here
)
It's as well solvable if you want only 1 out of Y groups, by using a random-element (as shown
here
)
But how is it done if you want to show - like in my case -
more than one
group out of a number of groups?
Edit: Sorry for the double post, but I think this question actually belongs rather here than in "Installation & update issues".