3 ms·
Cute, but dreadfully silly. The giveaway is the handling of uncertainty. That's too many decimal places for some of these measurements: 10um (0.01mm) is not re
by exmadscientist 7mo ago
Cute, but dreadfully silly.
The giveaway is the handling of uncertainty. That's too many decimal places for some of these measurements: 10um (0.01mm) is not reliably measurable by a cheapo caliper, and even trying to do it with a good caliper or micrometer, you'll find that everyday objects simply cannot be reliably straightforwardly measured with that level of precision. (You need cleaning procedures, standardized handling, standardized sampling, etc.) And quoting "4.1g (5.1% too heavy)" versus "4.0g (2.6% too heavy)" is just absurd: that last digit really doesn't mean much. So don't treat it like it does.
For example, on my random first d6 at hand, I get 4.47g from my nice scale and somewhere between 14.82 and 14.85 mm on the first face dimension, depending on how I measure, from my Mitutoyo caliper. I have a micrometer in the shop, but you can see that it'd be pointless to go get it. The next two faces are (14.79 to 14.84) and (14.76 to 14.87), so it's consistently like this.
Likewise, χ² to five decimal places isn't terribly useful... especially since you haven't really described the test you're running....
In general there's a lot of "look at me make measurements" here that might be impressive. There is very little "what is the true value of this measurement, and how well can we assert that", and simply not enough "is this the right thing to be measuring, and how much does that factor matter". That last one is critical: the actual weight of a die is, I think, not important at all. It's weight distribution that matters, so who cares about 0.1g of difference. Unless you're making a batch uniformity claim? But really this evidence just says more about your measuring equipment. And it's well known that different color resins, especially black, white, and red, are pretty differently loaded with pigments, so they have different properties. You can't just expect them to be the same, but the author seems surprised that they aren't.
And then we get to "These dice are safe to use" without any real description of the criteria or threshold. I say "this report is not safe to use (for serious purposes)"!
It's cute, it's a fun little minute to read on the internet this morning. But it's silly, and if my students back in the day or coworkers today sent it to me, they'd be getting red ink and remedial lectures in measurement uncertainty.
- tomcatfish 6mo agoThis reply is smug but dreadfully silly. The giveaway is the handling of information and curiosity. You argue for throwing both away, and it's not clear why. When the author takes away more decimals than they should, the article becomes useless. When the author leaves in more decimals than they should, I round "with my eyes" to my desired precision. As a bonus, I can take their numbers and spot-check them easily. The author put up a fun piece on a board game review website and summarized that the dice are fine. You ask what the threshold is, I say use your brain and eyes to pick one. We only need to read this once, not grade 200, so we don't need to invent an arbitrary cutoff. If you treat students or coworkers in this way, I hope it is clear to them that you respect rubrics more than the actual "Ask a question, gather data, answer it in public" scientific process and that they do not mistake stodgy rules for must-follow procedures. It would be a shame to scare people off from rolling dice on the internet because someone may say there are too few p-values or too many decimal places.
- exmadscientist 6mo agoI'm actually the anti-rubric guy! What matters to me is whether your arguments are appropriate to support your conclusions. Not whether you jump through the right hoops. This guy played it straight: these measurements, this result, that conclusion. But the evidence chain was bad: results couldn't be derived from those measurements, and conclusion couldn't be derived from those results. So I called it out. This is literally my day job, so I don't really like seeing poorly reasoned research, and maybe I'm more sensitive than most. But if you're going to play it straight, I think you should get it right. If that means you use a lot more weasel words, so be it -- if something is your opinion I can't argue with it. But when you state it as a fact, you better be able to back it up.