Access database design question

Hello.  This is just a general concept question. Trying to see if anyone else out there has attempted something similar and how they handled it.

I'm looking to create a questionnaire database in Access that will be sent to recipients. They will be required to answer the questions (by entering data in textboxes or whatever on database forms) and send the database back to me.  What I'm looking to do is try as best as possible to prevent them from returning the database with some questions unanswered. I want to require all questions to be answered. Any thoughts on how to accomplish this?

I do want them to be able to skip over questions if they need to and return to them at a later time or date. So I definitely don't want something where they can't advance to the next question until the current one is answered.  I was thinking possibly that a WORD document with the required answers could be generated and only generated once all questions are answered. However, I ultimately need the data in a database, so I'd have to wind up transferring the data from the WORD documents back into an Access database.  Possibly have Access create a new database once all questions have been answered and have the recipients return the newly created databases?  Or am I way off course? Thanks.