Although it is not clear to me why you suggest putting the equation into "sub-question" line, I have tried it this way and it still does not work for me...
The validation rule you have suggested works great!
But... It does not prevent from the submission of a too short passage. My idea is to request a respondent to write some meaningful text in the field by "imposing" the minimum number of characters for the entered text.
Dear Denis,
Now I have tried your suggested solution for the whole survey preview - it works perfectly and exactly the way I wanted! Thus - many thanks for your great help.
In my previous mail I referred to only the PARTIAL preview of the section instead of the survey as a whole.
Hi life LimeSurvey!
best
alchv
