My survey composes of mandatory questions and optional questions.
Thankful to the powerful LimeSurvey build-in function of checking and warning for unanswered mandatory question, the issue for mandatory questions are already nicely handled by showing a pop-up alert message box and highlight the concerned unanswered mandatory questions in red.
However, I would like to know if there is also some similar build-in function for optional questions?
As it is not uncommon that survey participants usually makes careless mistakes by overlooking some optional questions which are nonetheless important to academic research survey. We do not want to make those optional questions become mandatory simply because those questions are not compulsory to research study. However they are still playing an important role to critically affect a research result.
Anyway, the way I would like to make is to draw participant's greatest attention before submission, simply wither [1] a pop-up alert box or [2] by showing a conspicuous text on the question pages, or any page before submission.
Would appreciate your greatest help if you could offer your great idea and share your experience!