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Fair coins tend to land on the side they started (2023)

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Re: Fair coins tend to land on the side they started (2023)

#131

Post by dfxm12 »

chongli wrote: post #122
lcnPylGDnU4H9OF wrote: post #117

Earlier quoted context omitted.

There is a [video presentation of the paper]( https://www.youtube.com/watch?v=-QjgvbvFoQA ) which does a good job of explaining the inspiration for the study within the first few minutes. It sounds like what they were intending to study is the actual variance that is introduced, on average, by imperfections in throws conducted by humans. Unless that's mistaken, it's a fair point to consider the n=48 here. Did they di…

Yes and what immediately jumps out to me as a source of bias is that they asked this small group of 48 coin flippers to flip thousands of times each. I would’ve thought it would be obvious that when you ask people to do something thousands of times they might do it in a different (and biased) way than someone doing that thing only once. Get a hundred thousand people to flip a coin once each and then see what happens!

Get a hundred thousand people to flip a coin once each and then see what happens!

Of all the stats we collect in sports, I wonder if someone has info on coin tosses in sports like American Football, Tennis, etc. I wonder if there are even rules regulating how a coin should be tossed in different sports...

Re: Fair coins tend to land on the side they started (2023)

#132

Post by halgir »

KwisatzHaderack wrote: post #109
acyou wrote: post #96

The paper looks like it has a large sample size, but it actually has a sample size of only 48 testers/flippers. Some of the videos of those testers show very low, low-rpm coin tosses, we're talking only 1-2 flips. Where they also flipped thousands of times, presumably in the same way. So there is actually a very small sample size in the study (N = 48), where testers that don't flip properly (low rpm, low height, few…

> only 48 testers/flippers I assumed they did these coin flips were done using a machine. But I guess they wanted to test if human flippers because they wanted to make claims about the human coin flip phenomenon.

If you programmed a machine to flip a coin in the same exact way every time, would you not expect the coin to land the same way every single time? If you program some randomness into the machine to simulate human flipping, then you'd simply move scrutiny from the coin to the machine's programming.

I think the result could be better described as "humans tend to flip fair coins to land on the side they started".

Re: Fair coins tend to land on the side they started (2023)

#133

Post by dylan604 »

fluoridation wrote: post #124
chongli wrote: post #122

Earlier quoted context omitted.

Yes and what immediately jumps out to me as a source of bias is that they asked this small group of 48 coin flippers to flip thousands of times each. I would’ve thought it would be obvious that when you ask people to do something thousands of times they might do it in a different (and biased) way than someone doing that thing only once. Get a hundred thousand people to flip a coin once each and then see what happens!

What's more, from the numbers cited it sounds like they had 48 people do nothing but flip coins for 8 hours (avg. 15 flips/min). Whether continuous or with breaks, there's no way you won't become seriously consistent. 7000 flips is many more flips most people will perform in their entire lives.

In some circles, they'd make a post about how their "AI" flipped a coin 8000 times.

Waiting for the HNer that likes electronics hacking to Show HN: My coin flipping robot I built over a weekend for consistent flips.

Re: Fair coins tend to land on the side they started (2023)

#134

Post by sans_souse »

thought experiment: if we design a mechanical arm to enable coin flipping utilizing advanced tech to establish fine-grained adjustments and calibrations to effectively reproduce results with any given coin to and work out formulas to arrive at these results; are we currently or will we ever be able to say with absolute certainty what any given coin toss's result will be?

Re: Fair coins tend to land on the side they started (2023)

#135

Post by nfw2 »

BiteCode_dev wrote: post #33
cgag wrote: post #24

I wouldn't be surprised if there is something to it, but I suspected they didn't use legitimate coin flips (because it seems like a large amount of people can't really flip a coin), and looking at the videos confirms it, at least for the flips done by Bartos: https://osf.io/6a5hy/ They're very low RPM and very low time in the air. Nothing I would accept for any decision worth flipping a coin for.

That's not tossing a coin, that's barely throwing it in the air. To me this kills the credibility of the entire study and of the authors. Sure, there may be something to it, but people will have a very different thing on their mind unless they check the video, which I wouldn't have done without your prompting. It's unlikely they don't understand how misleading it is. And somehow I have the intuition a proper coin tos…

I think it's still noteworthy that what many people consider a "fair toss" is not in fact a fair toss. In other words it's interesting from an applied psychology perspective even if the physics of the phenomenon isn't particularly interesting.

Re: Fair coins tend to land on the side they started (2023)

#136

Post by anigbrowl »

acyou wrote: post #96

The paper looks like it has a large sample size, but it actually has a sample size of only 48 testers/flippers. Some of the videos of those testers show very low, low-rpm coin tosses, we're talking only 1-2 flips. Where they also flipped thousands of times, presumably in the same way. So there is actually a very small sample size in the study (N = 48), where testers that don't flip properly (low rpm, low height, few…

testers that don't flip properly

Clearly the coin flips at the beginning of sports fixtures need to be assessed by a panel of highly skilled judges who can pronounce on their validity. We'll also need local, regional, national, and international organizations to train, select, and maintain the quality of coin flipping judges and to maintain the integrity of the discipline while moving forward as new coins are minted and different sorts of flipping styles are proposed by. Membership of such organizations should be limited to those afilliated with the Ancient Order of Coin Flippers.

Re: Fair coins tend to land on the side they started (2023)

#137

Post by Aloisius »

outsidein wrote: post #13

Flip it twice. Once to determine which side is up at second throw. Reverse to counter bias at start of second throw. Then flip again for final result.

This won't fix the bias. It would be biased towards the obverse of the starting side up of the first flip.

Re: Fair coins tend to land on the side they started (2023)

#138

Post by jdlshore »

acyou wrote: post #96

The paper looks like it has a large sample size, but it actually has a sample size of only 48 testers/flippers. Some of the videos of those testers show very low, low-rpm coin tosses, we're talking only 1-2 flips. Where they also flipped thousands of times, presumably in the same way. So there is actually a very small sample size in the study (N = 48), where testers that don't flip properly (low rpm, low height, few…

The paper is an experimental validation of a previous paper that presented a statistical model. The experiment found the exact results predicted by the model. The reason for the non 50/50 result is precession of the coin.

Re: Fair coins tend to land on the side they started (2023)

#139

Post by anigbrowl »

damidekronik wrote: post #19
thih9 wrote: post #15

This paper is also this year's Ig Nobel Prize winner: > Probability: A team of 50 researchers, for performing 350,757 experiments to show that when a coin is flipped, it is slightly more likely to land on the same side as it started. source: https://en.wikipedia.org/wiki/List_of_Ig_Nobel_Prize_winners...

From this year's Iq: Botany: Jacob White and Felipe Yamashita, for finding that certain plants imitate the leaf shape of nearby plastic plants and concluding that "plant vision" is plausible. This somehow doesn't fit the Iq award in my mind.

They 'need' to fill slots not that the IN awards have become an annual media event (presumably yielding some profit) so they've taken to mocking perfectly legitimate research as long as it is in some way scatalogical or counterintuitive. I lost interest in the Ig Nobel prize as a result; they've gone from an intermittent amusement to a celebration of ignorance.

Incidentally the plant mimicry thing seems to be a defense against herbivorous mammals. It was previously theorized that the shape information was transmitted by symbiotic bacteria; the ability to imitate fake plants is a genuinely perplexing result imo.

Re: Fair coins tend to land on the side they started (2023)

#140

Post by askvictor »

anigbrowl wrote: post #136
acyou wrote: post #96

The paper looks like it has a large sample size, but it actually has a sample size of only 48 testers/flippers. Some of the videos of those testers show very low, low-rpm coin tosses, we're talking only 1-2 flips. Where they also flipped thousands of times, presumably in the same way. So there is actually a very small sample size in the study (N = 48), where testers that don't flip properly (low rpm, low height, few…

testers that don't flip properly Clearly the coin flips at the beginning of sports fixtures need to be assessed by a panel of highly skilled judges who can pronounce on their validity. We'll also need local, regional, national, and international organizations to train, select, and maintain the quality of coin flipping judges and to maintain the integrity of the discipline while moving forward as new coins are minted…

I was more thinking we'll need a Department of Randomness (or Ministry of Randomness for Westminster countries)
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