As a teacher Prof. Diwan has a no-nonsense style of teaching that makes his class refreshingly informative. His classes have an impromptu feel to it that makes a student comfortable, encouraging discussion or asking doubts, almost as comfortable as learning from a peer.
He has an excellent style of grading. In a subject such as Algorithm Design and Analysis, where there is no standard(or even close) answer, he somehow always manages to gauge correctly how far the examinees have understood what was required. All this in spite of grading every paper himself, which is no mean task considering how complicated some of the answers can get in this course(Algorithm Design).
Besides grading, he is so far the best professor I have learned from. His ready answers to doubts a student might ask, give you the feeling he left out certain details on purpose, so that doubts could be framed, so that we analyze the algorithm right there. His deep knowledge in his field can be understood from his ability to come up with nice counter examples to support or discard questions raised by the students.
(Added by Naman)
The examinations and tests conducted throughout his course are equipped with questions which require a deeper level of thinking and test the understanding of the exam-taker. More often than naught the questions were such that they provide a stern check of the basic concepts or provide a deeper insight into a particular area. Most of the students in the class found the examinations well complemented with the course material and helpful towards enhancing the understanding the subject as a whole.
(/Added by Naman)
What is extremely impressive is the way he comes up with answers instantaneously, on every single doubt that is raised throughout the course. And I mean all, not almost all. Besides, he really knows his subject well. He is always perfectly prepared in class, and has the entire course of action planned out. He is also probably the smartest person I have ever come across. Also, his aim with his courses is to allow students to learn, and use their creativity and imagination, rather than use strict grading policies to stifle freedom.
The best things is, he never leaves a student in doubt.He has such a “deep” understanding of things( not only subject,but also understanding the students way of thinking) that he can easily crystal clear the doubts, by one way or another.And throughout the course, he tried to help us improve our ‘thinking way’, the essence of the course.
(sushil)Well, he is the best teacher I have ever seen. The fluency with which he teaches, his ability to produce instant counter-examples for wrong algorithms, and the way he does the checking clearly left me mesmerized whole semester. I am not able to recall a single instance where he had stopped and thought before answering any doubt. It seems as if through the course of his long teaching career, he have clearly judged what all the students can think!! There was never ever any scope of marks increment in the exams. He was always able to judge what the student have thought before answering a particular question and even if it was not written properly he awarded accordingly. I think this teaching practice should be taken into consideration by every instructor. What he aimed at is student should learn the concept and think. We all really enjoyed the course.(/sushil)