@umbra21 - You can still ask those kinds of questions if you need to without revealing who has what kind of opinion. Just make sure that the majority of data isn't linked to any questions that could possibly identify people. So you won't be able to say something like "20% of women in this class didn't enjoy the class" but you will be able to give the overall percentage for everyone.
There are computer programs that will do this kind of compiling for you and I think websites like Survey Monkey will do it as well.
It's really important to be able to conduct proper anonymous surveys because people have to have confidence that they aren't going to get into trouble for their opinions or experiences. Without that confidence they will just refuse to fill out surveys.