fbartos

5 ms·

1.
by fbartos 1y ago
The coins are as likely to fall on heads as on tails, so they are not biased for any of the sides. People flipping them however introduce bias due to the wobble of their tosses.
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Paper with 350,757 coin flips showing bias published in JASA(doi.org)
3 points by fbartos 1y ago|3 comments
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by fbartos 1y ago
Paper showing that "Fair Coins Tend to Land on the Same Side They Started: Evidence from 350,757 Flips" circulating here a couple of years back ( https://news.ycombinator.com/item?id=42181345 ) is now published in t
4.
by fbartos 2y ago
We did not. However, we find it highly unlikely since everyone was incentivised to upload as much as possible, and the number of coin flips determined the order of the manuscript. Also, we did some basic analyses to check irregularities in
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by fbartos 2y ago
Yes, there is indeed a lot of heterogeneity in the bias between flippers and we are going to put more emphasis on it in an upcoming revision. However, it's hard to tell whether there are two groups or a continuous scale of increasing b
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by fbartos 2y ago
> In each sequence, people randomly (or according to an algorithm) selected a starting position (heads-up or tails-up) of the first coin flip, flipped the coin, caught it in their hand, recorded the landing position of the coin (heads-
7.
by fbartos 2y ago
Hi, I'm the first author of the manuscript, so I thought I could answer some of the questions and clarify some issues (all details are in the manuscript, but who has the time to read it ;) Low RPM tosses: Most of the recordings are on
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by fbartos 3y ago
Yes, I mentioned that in the original paper but it got eddited for some reason.
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by fbartos 3y ago
It's not about the number of rotations at all. I doubt that you can control it at all even after dozens of hours coin flipping (I did more than 20h and I can't eveb guess how many rotations the coin made) Diaconis, Holmes, and Mon
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by fbartos 3y ago
That's actually not completelly accurate. The study protocol ( https://osf.io/hkv8p ) describes the procedure in greater detail. People were pressing one button for heads and another button for heads (which we deemend le
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by fbartos 3y ago
I personally did 20,100 flips and I can assure you I have no clue how to control the flip. I centrally got much better at flipping and catching the coin in hand without dropping it---which takes some practice on its own. (I know that there
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by fbartos 3y ago
There was indeed a lot of variation in the height of the tosses. I however disagree with the conclussion: two of my friends at the video had the most different height of tosses (one tossed thrice as hight as the other one), yet both of them
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by fbartos 3y ago
You are absolutely right :)
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by fbartos 3y ago
We told people that the coin has to flip at least once (which would bias it for the opposite site). Whenever instructing people, I tried to explaining that the coin flip should look like you were trying to determine an outcome of a bet. You
15.
by fbartos 3y ago
Not neccessarily because spinning and bouncing coins are often much more biased then flipped coins. (Unequal weight distribution on the side can bias a spinned coin while it doesn not bias a flipped coin. There are a couple of studies on it
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Fair coins tend to land on the same side they started(arxiv.org)
377 points by fbartos 3y ago|265 comments
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by fbartos 3y ago
About a year ago, we embarked on a quest to answer one of the most intriguing questions: If you flip a fair coin and catch it in hand, what's the probability it lands on the same side it started? Today, we are finally ready to share th
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How fair is a fair coin flip? – Contribute to a scientific experiment
2 points by fbartos 4y ago|0 comments
19.
by fbartos 4y ago
Hi all, I'm one of the authors of the reply and it was very interesting reading so many diverse thoughts and comments. I would love to respond to all of them, but it would take ages. Luckily, Stuart Ritchie (@StuartJRitchie) wrote an a