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903 points tux3 | 1 comments | | HN request time: 0.202s | source
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jerf ◴[] No.43546861[source]
One of my Core Memories when it comes to science, science education, and education in general was in my high school physics class, where we had to do an experiment to determine the gravitational acceleration of Earth. This was done via the following mechanism: Roll a ball off of a standard classroom table. Use a 1990s wristwatch's stopwatch mechanism to start the clock when the ball rolls of the table. Stop the stopwatch when the ball hits the floor.

Anyone who has ever had a wristwatch of similar tech should know how hard it is to get anything like precision out of those things. It's a millimeter sized button with a millimeter depth of press and could easily need half a second of jabbing at it to get it to trigger. It's for measuring your mile times in minutes, not fractions of a second fall times.

Naturally, our data was total, utter crap. Any sensible analysis would have error bars that, if you treat the problem linearly, would have put 0 and negative numbers within our error bars. I dutifully crunched the numbers and determined that the gravitational constant was something like 6.8m/s^2 and turned it in.

Naturally, I got a failing grade, because that's not particularly close, and no matter how many times you are solemnly assured otherwise, you are never graded on whether you did your best and honestly report what you observe. From grade school on, you are graded on whether or not the grading authority likes the results you got. You might hope that there comes some point in your career where that stops being the case, but as near as I can tell, it literally never does. Right on up to professorships, this is how science really works.

The lesson is taught early and often. It often sort of baffles me when other people are baffled at how often this happens in science, because it more-or-less always happens. Science proceeds despite this, not because of it.

(But jerf, my teacher... Yes, you had a wonderful teacher who didn't only give you an A for the equivalent but called you out in class for your honesty and I dunno, flunked everyone who claimed they got the supposed "correct" answer to three significant digits because that was impossible. There are a few shining lights in the field and I would never dream of denying that. Now tell me how that idealism worked for you going forward the next several years.)

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1. thelaxiankey ◴[] No.43551519[source]
'flunked everyone who claimed they got the supposed "correct" answer to three significant digits because that was impossible.' while I've never seen anyone flunked for this, I certainly have taken off substantial amounts of points, and seen others do the same, for 3 significant figures when 2 is the absolute highest reasonably possible (and realistically, one sig fig was what we actually wanted).

I've run the exact lab you're describing, and I think we gave full credit for anything between 5m/s^2 and 20 m/s^2 provided there was some acknowledgement that this was at odds with what was expected. We very often would check in halfway through class and either tell the kids what they were doing wrong, or even tell them to write something 'this is at odds with literally all known science and I think I don't trust this'. For this particular lab, I've never seen errors as large as the ones you've described, so your lab was likely very poorly set up.

In other cases, I've made extra time (and allow students to come in) in case their numbers were so weird as to be problematic; just depends on the lab. Any teacher worth their salt will do this. It's a shame the teachers you had were terrible and incentivized bad stuff.

If being in a lab has taught me anything, it's that doing good science is often morally difficult. Sticking by your guns is hard.

But you are right in some sense: there are definitely incentives to... misreport. The best we can do as teachers is to reduce those as much as possible and reward kids/students for being honest.