I am in the middle of the surevy and I can see what folks are saying. The first question asks whether I am in a sorority. If I wasn't then I would not be taking the survey, right?
I clicked on the NPHC link and it says NPHC at the top of the page but the questions are reminiscent of NPC orgs.
Also, for some questions, you would get better data if you allowed multiple selections.
I put n/a on the sorority history information because I am not sure of the point to this section of the survey....
Your project needs a lot of help. Please listen to the sage advice you have been given.