Advanced Survey Formatting
DEMO 1: data filtering and custom layout
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* This is a fixed-type question marked as required.
For this question, respondents must explicitly choose a response option.
* When a fixed-type question is marked as required but allows multiple options to be chosen (such as this question), users must explicitly mark at least one option.
* Exactly two checkboxes must be checked as a response to this question.
Because this question is also marked as required, users cannot skip it without providing an answer.
This question requires at least two response options to be chosen.
Because it is not marked as required, respondent may skip it completely; but if they provide an answer, no less than 2 checkboxes must be checked.
Here we use advanced formatting options such as:
1) placing all response option in one line, and
2) randomizing the order of options (each time you reload the page, they should appear in different order).

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This question has an "Other, please specify" field.
Note that the field is disabled unless a corresponding option is chosen. This prevent dubious responses such as marking "Option 1" and putting some text into the "Other please specify" field at the same time.

If you have to allow several response options to be chosen, use checkboxes ("Other please specify" field is supported for checkboxes, too).