1  Start with the question

You grow into your research question through reading, writing and discussion.

Read widely. Follow the researchers whose work you admire and see what they’re actually doing. Pay attention, too, to the anti-mentors: people or bodies of work that make you think “I don’t want to do it like that.” Both are useful. A mentor doesn’t have to be someone you speak to. A mentor can be someone you only ever meet through their writing.

Write to think. Writing does more than record your ideas; it forms them, because the act of writing structures your thinking. Write your ideas down, and I’d encourage doing it by hand, pen and paper, because writing by hand makes you think differently than typing does.

Talk to people. Talk to your mentors, talk to experts, talk to peers, go to conferences, watch people give talks, watch talks online. And talk to people who aren’t experts: if you can explain your idea simply to someone outside the field, you understand it better than if you can only say it in jargon.

Do enough of this and your question gradually narrows itself down. It isn’t a scientific process in the sense of running experiments; you’re just circling in on the general area you want to work in.