I actually really enjoyed my Houston interview 🙂. it was really laid back and everyone was SOO friendly. The interview had one professor and a student, both of who asked questions. I actually talked a lot to the student that was interviewing me at lunch and we got along great. I think that really helped settle any nerves that I had. I didnt have to write anything ether. Dont worry about it. I'm sure you will do great!
Hope that helps