6.1 What do the interviewers want?
As discussed above, prospective supervisors will want to be shown that you have your own ideas but also that you are open to developing those ideas, and receptive to guidance. Your research proposal is therefore a starting point for exploration, not a rigid specification. You may be asked about connections to other ideas. If so, be ready to pick up on those and discuss them, not reject them, even you can’t instantly tie them to your interests and previous work. (It’s perfectly acceptable to say that a suggestion is interesting and you will think more about it, assuming of course that you follow through on that and do think about it later.)
If you are being interviewed for a university place, such as a studentship, be ready to answer explain what attracts you about this specific opportunity. The prospective supervisors and other university representatives will want to know that you want to come to their university and department/school, and have found out about it. Before the interview, your searching should have familiarised you with the specialisms of the academics, especially the prospective supervisors, and you should be ready to explain what interests you about their work and how you see it contributing to your proposed project. Remember that the people who are considering offering you a place will be looking for someone who will join in and be open to teamwork, not a lone genius! Also, if the university is distant from your current place of residence, the interviewers will want to hear that you will be present in the research community (the pandemic allowing) and are not planning simply to take the funding while continuing a separate life elsewhere.
At the end of the interview, you will have an opportunity to ask questions, and this is an opportunity to clarify points you are uncertain about, and also to demonstrate (again) your interest and willingness to contribute (for example, you might ask about opportunities for part-time teaching).