Whoa -- I assumed I would get a notification when you replied, but apparently not. Glad I checked the thread again!

But what’s the value in a take-home exam, if we assume that the intent is to be closed-book but with effectively unlimited time? Presumably that means it’s a problem roughly on the scale of an assignment, but they’re not meant to be able to look up their notes, review the lecture material, etc.?

Interesting point! I definitely see where you're coming from here... If I gave a take-home exam, I would want students to use their notes, some online resources, etc. I just wouldn't want them to copy an exact answer from online or other students. That may just be impractical today.

For what it’s worth, I’ve seen first hand that code copy-detection tools are honestly not actually all that great.

100% agree. I had small enough classes that I could check for plagiarism more directly. And, what you said later is spot on -- I think most students who cheated were not subtle enough to make hard-to-detect changes. Though, if they were, I wouldn't know they cheated, so... hard to say.

I’m actually not 100% sure on what “proctor” means, but based on how I’ve seen it used in this thread, I gather the two are the same?

Yep! Based on an online dictionary that said "proctor" was the US version of invigilator :)

Anyway, you make some great points, so thanks for the discussion!