Introduction: They ask you about related experience and what you would do in relevant situations likely to happen.
Testing: They give you a sheet of SAT-level questions to answer, to see where you're skill level is at.
Simulation: They ask you to simulate a short tutoring session by going over both an English and a Math problem from the test you just took. It's pretty straight-forward. The interviewer was very kind and also gave feedback between problems, allowing me to get more comfortable and confident as the interview went on.