Be careful! Most likely, the principal already knows one answer to this question.... that file folder on his desk with your name on it probably includes a letter from your supervising teacher.

Use this as an opportunity to talk about yourself. Share something the principal doesn't already know. Here are a couple of ideas:

My supervising teacher would probably tell you that I prepare myself well and that I put in the extra effort to meet the needs of "special students." If she was here with us she might describe how one of my great lessons got destroyed by a fire drill one day. By the time we got back inside the building, there were only about five minutes left in class and I really wanted to set up this discussion on Lincoln's Gettysburg Address....so here is what I did....

My supervising teacher told me I was a quick learner. I came to my student teaching experience with a million ideas, 99% of them pretty impractical. He talked me through a couple and then let me fall on my face with my "long-division-game lesson." I can laugh about it now, but at the time, I was devastated. I learned that the first thing I needed to do was organize the class and get them prepared for learning. So I designed some lessons that would get more students involved.....