Given the option to talk about anything, I'd be concerned if the candidate couldn't pick something in 10 seconds. I'd be concerned if they could. It might sug

Given the option to talk about anything, I'd be concerned if the candidate couldn't pick something in 10 seconds. I'd be concerned if they could. It might suggest they are not all that interested in too many things. Or are hyper-focused on just one thing. There are two things at work here. Picking something you are interested in, and deciding if you can actually explain it well in five minutes. Figuring out the latter would take me easily more than 10 seconds. It's not a matter of picking something you can on about for five minutes. It's about be able to explain it to someone with no prior knowledge, and have them understand what the hell you were talking, and what's most important about it, when you are done. Now that the article is back up, it see it has this: Take as much time as you want to think it through, and let me know when you want to start. So another question is, is it better to allow "as much time as you want", or set some time limit in picking the topic? Practically speaking, if someone is still musing after an hour I think the jig is up, so there's at least some practical upper limit. But how does it influence the candidate to think there is a fixed prep time versus having unlimited time?