XLSForm Template: Don't Select "None of the Above" with Other Choices

I want to share with you a useful XLSForm constraint that you can use when you create digital questionnaires for Kobo Toolbox, ODK, Ona, or SurveyCTO.  Someone recently asked me this question:

“How can I create a constraint such that respondents can’t select “I don’t know” and another option.  I want to create a constraint that prevents selecting “I don’t know” and any other option from a multiple_select question.”

This is such a good question.  And it is very common in humanitarian and development questionnaires, where we give a list of options and say “select ALL that apply”.  And then at the bottom of the list, we might have options like:

- Not applicable

- I don’t know

- None of the above

But it wouldn’t make sense if the questionnaire allowed you to select “None of the above” with another option also.

So…there is a great constraint that you can use in your XLSForm to prevent this from happening.