I am preparing for my upcoming phd viva and came across a list of questions that might be asked during the viva. One of them asked "where did you draw the line on what to include in your lit review". I was a bit confused by this question and I was wondering if you could provide some guidance on how to structure the answer. Thank you!
One simple answer is (leave away those aspects that don't apply to your situation):
First, I systematically thought about the different directions in which related work may exist. To make sure I did not miss any relevant directions, I consulted with my advisor/other researchers and checked the related work of the related work I initially looked at. For each identified direction, I considered a handful of prominent papers, until a point was reached where new papers did not add substantially new ideas, but just variations of the ones I already had covered.