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Comment by LeifCarrotson | Hacker News Reader

Hands-down, the best presentation and note-taking math class I recall in college (discrete mathematics, a graph theory course, heavy on drawings) was run through a Wacom pen display on the lectern, linked to a projector. The professor could accurately and cleanly draw the required notation with his hand flat. Why erase when space is infinite, just scroll and/or zoom in the desired direction. A full color spectrum was available. If something needed a chart or other graphic to better explain, that was a swipe away. And the output of the lecture was always available after class, so you could take notes on the important parts or follow-up questions, instead of having to try to scratch everything he narrated as fast as he could speak and write. It just made so much sense.

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That sounds similar to the approach my Prealgebra teacher used in 1994. She had an overhead projector with a roll of plastic transparency sheet attached. She wrote across the bottom of the projector and then rolled it up as she went along. Different color pens were available. You could follow along and understand the process, and there was plenty of time to take notes as the material rolled up the screen.

I think that all of my math teachers in middle and high school used projectors with transparencies. It wasn't until college that most math and physics was on black boards. The major benefit of transparencies is that the teacher was always facing the class. So they could just look up to make eye contact with students.

I hadn't given it thought before, but I assume transparencies weren't as present in college because the room a given college class will be is essentially random. It's not an environment controlled by the person teaching. in high school and middle school, that was the teachers' classroom. The teacher stayed in their room, and we moved around. Projectors require more maintenance (bulbs going out!), and the college teachers would need to lug around their transparencies and pens. But all college classrooms have blackboards and some chalk.

It might also be due to lighting.

Overhead projectors require a fairly dark room, and only work well up to a certain size and distance. Much beyond that, their light gets too dim, and if it is a large lecture hall, you need a large projection with very bright light for everyone to see.

Then there's off-axis people who might find a projector difficult to read. In a small classroom, both of these issues don't really come into play.

A blackboard, however, can be seen in a brightly lit room, almost anywhere in the room, even if the room is very large. For the really massive size lecture halls, you can have multiple blackboards that span the width of the room, plus sliding and portable ones.

Each system has its benefits and detriments I guess...

> large lecture hall, you need a large projection with very bright light for everyone to see.

And the hard limit on how bright you can make that is that the lecturer is staring into that light while writing so you can only make it so bright before it becomes painful or damaging. Anecdotally when I was in elementary/middle school we'd sometimes have to work things out writing on a projector and it was tough sometimes and looking up you couldn't really see because your eyes had adjusted to the brightness of the projector. Maybe they could improve the lenses to spill less light out but it wasn't back then.

Absolutely true, and I didn't think about this. In retrospect, my intro physics courses (which were 90% engineers) were in such classrooms, and could not have used a projector. But the rest of my physics classes, and all of my math classes, were in rooms the size of my high school classrooms.

Huh, this sounds almost exactly like my experience too, down to the same year and subject! This was in Mexico, but our teacher was from the southern US, I believe. I wonder if it was a particularly popular teaching method of that year.

We had a lecturer who tried this with an early tablet computer (c2005) and IIRC, onenote. He got about two or three lines of equations on the screen at once before scrolling it off the top, so there was none of the ability to slow down, comprehend, then quick transcription that moving onto multiple blackboards allowed.

Having the last 10 minutes of progress, or more in special lecture theatres - allowed cross-referencing and observation that is hard to replicate with pre-prepared slides or with a single window of view.

Massimo Gobbino from Università di Pisa has been using this method for a while, he puts both recordings and notes online for everyone to learn from [0]. It's all in Italian though. It'd be amazing if this was done by more people around the world.

http://pagine.dm.unipi.it/gobbino/Home_Page/ArchivioDidattic...

Oh god that sounds just so incredibly good

My graduate stats teacher used a system like this and it was horrible. His handwriting was so bad on the tablet, but much better on the chalkboard.

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