I know it's a bit late since you've already created the questionnaire and I assume there are people who have filled it out, but I would recommend N/A as one of the answer options.
I couldn't finish completing your questionnaire because of the lack of "N/A" option among the answers. Sorry.
Good luck with your thesis anyway!
Last edited by LTN Phobia; Apr 5, 2009 at 6:41 pm
Reason: Was not very clearly written