One of the worst professors I have had at Columbia. I did not think he was that bad until the end of the semester, when he decided that it would be a great idea to e-mail his students about a final review session 1 hour before the actual review session took place, making an assumption that a. students would be awake at 10am to read this e-mail, and b. students check their e-mail CONSTANTLY and will have read the e-mail.
To top it all off, he refused to post the practice final online saying that it was our fault for not attending the review session.
Overall, a very disorganized professor, and not particularly great at teaching either. Homeworks were assigned erratically so we would not know what week a homework would be due, so it was definitely difficult to plan ahead.