Perhaps don't do it as an interview format (when you are interacting with them in person.) I say this based off your "I have been trying to get someone to sit down long enough for me to interview them for class." Honestly, when I am at the deaf club, the last thing I want to feel like is being interviewed. Yet, when ASL students come up to me and start chatting I am more than forthcoming when it doesn't feel "interview-like". I get enough of that from a job interview
Just friendly advice.