3 hours for us as well. When you start doing graduate level work, a problem could easily last over an hour. And many people will have false starts before they figure it out.

It's not a problem with homework assignments as they have multiple days to finish.

So the professor has to decide between poor data with high variance, or good data with lower variance.

> I'm pretty sure that having more time would not have helped the weaker students get through the Quantum Mechanics exam.

Funny you mention that. When I did my (undergrad) QM II exam, I likely got the highest score, and I'm sure my score was below 40%.

There just wasn't enough time.

I sat one exam at uni (in person, invigilated) for History and Philosophy of Science, which had no time-limit. You could take as long as you needed, whether that was one hour, five hours or all day.

Pretty much everyone still took three hours. But you felt so much calmer, knowing you weren't racing against the clock.

All of my exams were three hours as well. I don’t think there’s a single instance where more time would have helped me. If I didn’t immediately know the answer to a question, I’d just move on, then revisit. When you don’t know the material/answer, more time won’t help. But you do have to know how to take a test and manage your time.

A lot of challenging problems are not solved in one go. You work on it, don't get too far, and then you get more ideas later at night while cooking dinner.

Don't get me wrong - I'm sure people cheated even in my day. But this is the spirit - they're trying to give problems as challenging as they would for homework - and a lot of those classes have very challenging homework problems.

> Fast students are smarter.

Assuming this is true (others have already addressed a few of the many reasons it might not be), wouldn't that imply that practically all existing tests are already flawed? If you want to grade on time, every exam should be graded with a formula taking both the time and the correctness into account. A binary "fast enough" vs "not fast enough" is about as useful as a pass/fail class grade.

The exams that felt like the fairest reflections of my own knowledge were proctored in-person, closed book, and time unlimited. Of course, being time unlimited works better for quantitative/engineering exams. I haven't put much thought into more qualitative/liberal arts type exams.

> Fast students are smarter.

Dubious assertion.

> "smarter" here means how well the student will perform in a career in their chosen field. Fast + accurate is the ideal.

Still dubious.

Also, I don't know where you work, but in most of my jobs, career growth is not limited by speed with which you do the work. It's one factor among, say, 10. Most of the people who got ahead were not the fastest.

They're not trying to gauge who is the fastest. Or even the smartest. Just those who have the skills. In the real world, you'll rarely (as in, never) have to solve those same problems with the same speed you will in the exam.

In a lot (all?) of the jobs I worked, taking a day to solve a Medium level Leetcode problem was quite OK.

Are they? Or do they just have superior recall? Or maybe lack test-taking anxiety? Or write or type quicker or...?

Lots of reasons a slow student can be just as smart or smarter than a fast one.

Define “smarter” —- already a vague and overloaded term.

And then consider whether the point of the class is to test smarts, or something else.

I’d expect that’s not the intent of most undergraduate degrees.

Care to explain?