As a part of the academic program for the residents in the Department of Community Medicine at the University College of Medical Sciences, New Delhi, we have to give didactic seminars on different topics for the faculty members and the other residents. This is a great exercise not only in speaking and countering, but also, I think one learns the best when he studies something! I presented a short revision (not really short!) of the estimates of risk in epidemiological studies today.
Here is the presentation: