Having been involved in surveys and clinical studies for too many years, it is a common courtesy to explain precisely who you are and the purpose of any survey you undertake.,particularly as you are asking questions relating to health.
You Imply that you are supervising two students...
Oh dear! Intrusive questions (why ask earnings with no option for 'prefer not to say' ; poor questions; unclear purpose.
I have been writing questionnaires for years for clinical studies and you HAVE to consider each question carefully in terms of does it make sense in itself (suppose my...