I am a PhD student based in Canada and have a comprehensive exam coming up in 4-6 months. This is an exam I have been nervous about since I began my PhD in Machine Learning. I am fairly confident about the actual proposal and answering questions related to my field. What concerns me more is fundamental/background question as ML and statistics is so broad. Plus, I am a little on the older side and my memory is a little poor. In addition, my MS was in a very different field.

Have any students here taken a comprehensive exam? If so, what was your experience and how did you prepare? Is reading/making notes from a textbook a good idea? Or is preparing a list of topics and reading extensively about them a better option?

My advisor is very helpful and will be asking me questions throughout this period. However, I am not sure if those are actually enough.