I have had Alex twice as a TA for American History Courses. I have likes Alex a lot. He has a laid back style, runs discussions in a respectful manner, does not put people on the spot, poses interesting questions. I like his style. But do not let his seemingly casual style deceive you. He has a style that seems unstructured but he always comes to section very well prepared and with an idea of where he wants to go with the material -- although he is flexible about where the discussions go. He often relates the history to current events - this makes one think about why we study history.Do your assingments on time and well. Don't slack off. Your grade will suffer when you think that you got by with screwing something up -- you won't. I got zinged in my first course with my final grade because I thought he cut me a break on a couple of minor things. The next time, I worked my butt off and did not interpret "Don't worry about it" as I was let off the hook - he won't screw you, but he does his job. Clearly, he finds it distasteful to come down on anyone. He is sensitive to student workloads and has extended minor deadlines by a day or two without being asked. He grades fairly and is always great to talk to about projects, recommends helpful books and films. I found him to be a nice guy, and a good history TA. Actually, he's one of the better TA's I've had at Columbia. If you get a choice of TA's I can recommend his section.