How Do You Pick a Research Idea Worth Chasing?

Alex Zhang chooses which research idea to chase from about 10 or 15 different ideas he wants to do, and most of them are bad. He allows that an idea from someone who reaches out might actually be bad, yet it looks interesting. Some time goes into looking at it. If there is actually something there, the next few weeks go to really pursuing it.

He loves the PhD because there are times when he is just thinking about problems on a run or while playing tennis. He guesses he is not working then, and the time is the most fun. When he is really convicted about something, he drops everything and spends all his time thinking and working on the problem. Once he can just run experiments, the work becomes easy coasting again.