The hardest question in a dissertation defense is one outside your research scope. Candidates feel pressure to answer everything, but the smart move is to acknowledge it, say it's beyond your study, and express interest in future work.
What is the most difficult question you've ever heard asked in a defense?
The most difficult question for many people is something beyond the scope of what they've done, and they feel that they've got to know everything, so they try to answer it, and they have no idea what they're doing. But if they understand that they're probing and seeing if you understand the limits of what you've done, and you say, you know, it's a really interesting question. Based on what was the scope of this research, it's beyond the scope, but I'd really like to explore that in the future. It's you saying, that's a good question, but it's not part of my research. So you get really weird answers if people start thinking, I can't say no, I better answer this, and they can end up really confused.
