The Columbia interiew is very laid back and casual. I thought it would be more intimidating and challenging since it is an Ivy League school, but it wasn't. The interview is an opened file, one-on-one with a faculty member. Some questions that I was asked were: Why Columbia? Can you see yourself living in NY? What are you doing on your year off? Do you plan to specialize? What makes you stand out from the rest? How well do you work with a diverse group of people? Describe your leadership qualities. That's all I can remember. Keep in mind though that it was a conversational interview so it wasn't like the interviewer kept nailing me with questions one after another like I've listed them here. One final pointer: Be confident! A faculty member there and the dental students told us that the adcom likes to see confidence.