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Comment by mhartl | Hacker News Reader

It sounds like the tests are too easy.

You might be right that much or most of the higher pass rate is due to higher attendance, but it's also possible that students were learning plenty from section, the book, and working on problem sets. When I taught the analogous course (Physics 1) at Caltech, many of the students skipped lecture entirely. The failure rate was typically under 5%, and I guarantee it wasn't because the tests were easy.

One student I remember took it all the way: he skipped everything, including homework (which counted for 20% of the grade), but he got perfect scores on all four quizzes and on the final exam. According to the numbers he had an A- because of the 0 on homework, but everyone in the grading room agreed that was absurd, and so we gave him a flat A instead.

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First year physics is mostly review for a lot of incoming freshmen, especially if they did one or more AP classes in high school. I'm not suprised that some would do great even skipping the lectures.

When did they put freshmen on grades? When I was at Caltech years ago, first year was pass/fail.

Back then, Goodstein taught phys 1a. Fine lectures, unless you had read the chapter in advance. Then you noticed that his lecture was almost identical to the text, which made it hard to stay awake. Oh, and the retch session were taught by full profs, not grad students, so a lot of learning happened outside of lecture.

Highly qualified students have the option to test out of the different terms of Physics 1. (I know because I graded the placement tests for five years.) I suppose some of them take the course anyway to get an easy A, but this guy I'm talking about aced Physics 1c analytical track, an E&M course that uses Purcell, and very few high schools cover material that advanced. (It's well beyond even AP Physics C material.)

Regarding grades, here's how it shakes out nowadays:

  1st term: pass/fail
  2nd term: "shadow" grades
  3rd term: real grades

Shadow grades don't appear on your report card, and they don't count towards your GPA, but they are used for internal scholarship awards and recommendations.

Recitation section TAs in physics have been a mix of professors and grad students for as long as anyone can remember. Virtually without exception the best TAs were grad students (as measured by student reviews, section sizes, and exam results), though some of the professors weren't bad either. This jibed with my undergrad experience at Harvard: almost all my physics professors sucked, and by far my best instructor was the 22-year-old grad student who taught my freshman physics section.

The intro physics class at Harvard is graded something like:

k * homework_score + (1 - k * homework_score) * (final_score^extra_credit)

So you can do no homework and no extra credit as long as you ace the final.

It sure wasn't that way when I was there. ;-)

1. - 0.2 = 0.8 is typically a B-. Is there a different grading scale there?

Basically all classes at Caltech are curved. It actually makes a lot of sense, because it means you can make the tests really hard and leave plenty of room at the top, which among other things helps reduce the variance due to careless errors. (If you make a couple minor minus sign mistakes, but nail a hard problem most people miss, you still come out ahead.) In Physics 1, typically 90%+ was A+, ~82-89% was A.

curve?

I pulled this trick in my entry-level calculus class in college. They were so generous with extra credit that my marks should have meant that I got an A. But I didn't do any of the homework and the TA decided to punish me with an A-. I suppose I should have fought, but I'm epically lazy.

Lesson: if you're going to do something like this, don't assume that the people on the other end will hold up their end of the implied bargain. Either fight or do some token tribute.

or even their end of the /explicit/ bargain. I had a prof fail me, after announcing that the final grade would be the class grade. I never went to class, so he felt justified in ignoring my A-/B+... took me awhile to get over that slight.

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