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jimhefferon commented on Demystifying the regular expression that checks if a number is prime (2016)   illya.sh/the-codeumentary... · Posted by u/aquir
IgorPartola · 10 months ago
So in summary there is no special thing here about this being a regex: the program described by it basically just brute force tries to divide the given number by every number smaller than it, it’s just written in a way that isn’t obvious to understand.

That’s not to detract from the excellent post, just that this isn’t a mathematical trick that exploits some structure of primes but rather an incredibly clever way to write a computer program.

jimhefferon · 10 months ago
Everything is easy once you know how.
jimhefferon commented on Cooking with black plastic is particularly crucial to avoid   theatlantic.com/health/ar... · Posted by u/Jimmc414
hggigg · 10 months ago
I am mostly worried about the stress of things sticking to that like glue. Stress has physiological consequences.

I see people worrying about this shit while walking on cliff edges, honking down cans of energy drinks and puffing away on vapes. There are probably larger health and risk considerations to make in your life.

jimhefferon · 10 months ago
For those of us who don't walk on cliff edges, though, it is a concern.
jimhefferon commented on Do AI detectors work? Students face false cheating accusations   bloomberg.com/news/featur... · Posted by u/JumpCrisscross
simsla · 10 months ago
As a student of the previous generation, I much preferred exams with an oral defence component. Gave an opportunity to clear up any miscommunications, and I always walked away with a much better estimate for how well I did.
jimhefferon · 10 months ago
Hard to see, though, how to do that with hundreds of students in a room, and be reasonably uniform and fair about it.

An argument perhaps that there should not be hundreds in a room.

jimhefferon commented on Do AI detectors work? Students face false cheating accusations   bloomberg.com/news/featur... · Posted by u/JumpCrisscross
FloorEgg · 10 months ago
I have friends that started a startup trying to tackle this problem. They actually found ways for certain types of exams in certain subjects to make cheating exponentially harder and also provide less of an advantage, so much so that if the student is cheating they are effectively learning.

Some of their stuff works really well, and they have prof customers who love it. The CEO went on a tour to visit their biggest customers in person and several of them said they couldn't imagine going back.

Unfortunately as a whole the industry is not interested in it, aside from a few small niches and department heads who are both open minded and actually care about the integrity of the education. There have even been cases where profs want it and the dean or admin in charge of academic integrity vetoes its adoption. I've been privy to some calls I can only characterize as corrupt.

There is something deeply broken about higher Ed, the economics, the culture of the students, the culture of the faculty, the leadership... This isn't an AI problem it's a society problem.

When the students genuinely want to learn something and they are there for the knowledge, not the credit, cheating isn't a problem.

jimhefferon · 10 months ago
Can you say more about the startups stuff?
jimhefferon commented on Exploring Typst, a new typesetting system similar to LaTeX   blog.jreyesr.com/posts/ty... · Posted by u/judell
enriquto · a year ago
> Yes that works.

Oh, that great! My major point of friction with LaTeX is that using unicode is not straightforward. You sort of can, by including the right packages and using the right interpreters, but it imposes strange constraints involving the fonts that you can use and whatnot.

Regarding the usage, it's probably my fault. I tried to compile it locally and it didn't work at first (requires newer rustc version).

jimhefferon · a year ago
> My major point of friction with LaTeX is that using unicode is not straightforward.

Possibly you are describing how it used to be before the input encoding standard for LaTeX switched to UTF-8?

jimhefferon commented on Understanding the Limitations of Mathematical Reasoning in LLMs   arxiv.org/abs/2410.05229... · Posted by u/hnhn34
bob1029 · a year ago
> Now I guess you can pick up the goal post and move it.

The central problem with math is that you have an infinite amount of space within which to move these goalposts.

How many variants on this trial before we find a mistake?

What is an acceptable error rate?

jimhefferon · a year ago
At this moment, the error rate seems to be that of a beginning graduate student. Or at least, that's what Terry Tao thinks. That's pretty good.
jimhefferon commented on Identification of officer from Sir John franklin's Northwest Passage expedition   sciencedirect.com/science... · Posted by u/Hooke
jimhefferon · a year ago
Isn't Gambier the admiral who would not support Cochrane's fireship attack at Basque Roads?
jimhefferon commented on Learning 101: The untaught basics [pdf]   typeset.io/pdf/learning-1... · Posted by u/JustinSkycak
rahimnathwani · a year ago

  you have to tell them
Yup! Justin (who posted this to HN) is trying to solve that by having a software system tell students exactly which exercise to do next.

BTW thank you for freely sharing your textbooks.

jimhefferon · a year ago
Sure, you are welcome.
jimhefferon commented on Learning 101: The untaught basics [pdf]   typeset.io/pdf/learning-1... · Posted by u/JustinSkycak
jimhefferon · a year ago
I'm not sure who is the audience for this, but if it is students then it is not going to be very helpful, IMHO. For students to get it the authors must give concrete examples.

Let me pick on B, on spaced learning and interleaving. In those two paragraphs there are no concrete examples. If a student asks, "OK, I'm at the library and I have my book open. What do I do?" then the answer is not there.

I'll talk about college math because that's what I teach.

If you want students to learn what to do, you have to tell them. Maybe, "Set your timer to a half hour, pick out five problems, three from the current section and two from sections you did last week, and do them. If you get stuck take a peek at the answer, but don't peek until you are stuck. If you get really stuck, mark the question in your notebook and ask about it at the start of the next class. But under no circumstances just read the book." Then you have told them how to practice recall and to interleave in a way that they can actually do it.

Four half hours remembering how to do both current problems and also some from before for every hour spent in class is a good whack at learning the class's material, at least in the first two years.

Just using the two words recall and interleave is not enough.

jimhefferon commented on The centrality of stupidity in mathematics   mathforlove.com/2024/09/t... · Posted by u/ColinWright
jimhefferon · a year ago
In its impact on teaching, I'll say that based on teaching since 1979, students take feeling stupid as convincing evidence that their instructor is doing a bad job. No amount of assuring them that it is the gateway to enlightenment or however you put it will save you.

u/jimhefferon

KarmaCake day3407January 6, 2012
About
I teach college math. And, I have been fooling with computers and open-sourced software for far too long. For my free math texts and contact information see https://hefferon.net.
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