Adding and/or questions in ODK

1. What is the issue? Please be detailed.
I am trying to add a follow-up question to a 'check all that apply' question. The follow up question should appear if one, two, three, or four of the 5 answer options are checked. I coded it so that the following would result in the follow-up question appearing: ${cooling_center}="park" or ${cooling_center}="pool" or ${cooling_center}="public_cooling" or ${cooling_center}="other_shaded". However, this results in the follow up question only appearing if one answer is checked instead of multiple. I tried adding "and/or" instead of "or" between the options, and am looking online to try to find an alternative but can't find one.

2. What steps can we take to reproduce this issue?
You can take the steps above where you want multiple boxes checked to lead to a follow up question, but instead the follow up question only appears if one box is checked.

3. What have you tried to fix the issue?
I tried to use and/or instead of or, which didn't work, and look online for an alternative.

4. Upload any forms or screenshots you can share publicly below.
I'm somehow not able to find the right language to input - anyone who knows, please share! thank you!

Have you looked at using count-selected() instead? eg

follow-up question's relevant: count-selected(${cooling_center}) >= 1 and count-selected(${cooling_center}) <= 4

The fifth answer is ‘None’ which requires no follow up. Does the 1-4 below refer to the order that the questions are asked? So that the fifth answer wouldn’t create the follow up?

Also, do I input Q1 or the answer itself, like I had previously?

Thank you!

OK, try this instead:

count-selected(${cooling_center}) >= 1 and count-selected(${cooling_center}) <= 4 and ${cooling_center} != "5"

The 1 and 4 are the counts of how many options were selected; your stated criteria indicated at least 1 but no more than 4, hence >=1 and <= 4; hopefully that makes sense. [BTW I'm assuming above that you cannot select none/5 and something else... But to actually enforce that you will need a constraint of some manner]

For a select_multiple, you should use selected(...) not simple ${...} reference, see

Your example shows the expected behaviour, as all selected choice_names are stored in one string (the select_multiple variable) separated by one space and ordered as the choice_list.
So ${cooling_center}="park" will only be true, if ${cooling_center} only contains the "park" choice. But if "pool" was additional selected, the string, i.e. ${cooling_center}, would be "park pool", (corresponding to your choice_list order).