Thanks for the feedback, everyone. The survey is still open, so please feel free to take it. Garrett and MetalPanda, the reason we required answers is because we think the fact that you might not have heard of those groups is just as valuable as your thoughts about them if you had heard of them.
berky93: We've done a ton of other research leading up to this point to find out directly from participants what parkour is (and, for that matter, what free running is--and the differences between them). This survey is just one small (though important) part of the larger project.
Again, thank you for taking your time to complete this for us.