Please share so we get a pretty graph. ^^"
Okay, analysis time, here we go! First of all, a short disclaimer: I'm by no means an expert. It has been years since my last statistics class and I hardly remember anything. So take everything with a grain of salt. 😅 My basic method for analysing the result was K-S (Kolmogorow-Smirnow) tests. Very un-scientifically I throw the data against a bunch of different known distributions and fit the parameters to the data (I think the `scipy` library uses MLE as the fitting method) to see which one matches the best. I didn't test any discrete distributions because honestly I couldn't get fitting to work and I didn't want to spend a bunch of time on that. Note: Our data is discrete, so the absolute K-S probability values are going to be tiny. But since we are only comparing them between each other it should be fine (again: This is not scientific, but just for fun. ^^). I tested the following distributions: normal, beta, cosine, semicircular, von Mises, chi, chi2, gamma, Student's t Some of these distributions only work on the range [0, 1], so for the comparison I moved the data accordingly. The distribution that's the closest match is actually the gamma distribution. With a ginormous α value (1110.2) but moved and scaled accordingly. I wanted to plot it but Desmos just bugged out - understandably so. Additionally, since gamma can only deal with variables > 0 we'd additionally have to move it. Let's discard that one since I just don't know how to deal with that. ^^" The next closest is the chi distribution with a k value of 137. Again scaled and moved to accordingly. Same problem, though less sever - let's discard it. This brings us to our 3rd and 4th place: The normal distribution and Student's t distribution. Both have pretty much the same probability value in the test. Looking at the parameters it's obvious why that is: The parameter v is 82104712197. Since the t-distribution converges to N(0,1) with v tending to infinity, we can effectively call them identical. Let's give the win to the normal distribution since the t distribution would need to be scaled and moved (again) and because of this ridiculous v value I can't plot it anyway (Damn you, Γ-function!). ^^ Let's take a closer look at the normal distribution: μ = 0.1829 σ = 1.5710 So the mean value is actually quite good, but the standard deviation is almost 60 % too big. Looking at our graphs we can see that the overall shape of the poll result (blue dots) is way to spread out to fit the target distribution N(0,1) (red), but fits reasonably well to our calculated distribution (green). The obvious exception being the point at x=0 which is noticeably favoured by the participants. That was fun. I should do something similar again some time. 😊 (📎1) RE: Can we approach a normal distribution with µ = 0 and σ = 1? Please share so we get a pretty graph. ^^"
@sigmasternchen okay, so I didn't check the status of the poll, just the number of people voted, and somehow deduced that "well, most people would probably vote zero, but also people who don't will overestimate the need to vote on +/- 2 or 3. Among plus and minus one, more people would chose the positive number probably, so to balance the distribution, I should vote -1".
Does it make sense? probably not.
Okay, analysis time, here we go! First of all, a short disclaimer: I'm by no means an expert. It has been years since my last statistics class and I hardly remember anything. So take everything with a grain of salt. 😅 My basic method for analysing the result was K-S (Kolmogorow-Smirnow) tests. Very un-scientifically I throw the data against a bunch of different known distributions and fit the parameters to the data (I think the `scipy` library uses MLE as the fitting method) to see which one matches the best. I didn't test any discrete distributions because honestly I couldn't get fitting to work and I didn't want to spend a bunch of time on that. Note: Our data is discrete, so the absolute K-S probability values are going to be tiny. But since we are only comparing them between each other it should be fine (again: This is not scientific, but just for fun. ^^). I tested the following distributions: normal, beta, cosine, semicircular, von Mises, chi, chi2, gamma, Student's t Some of these distributions only work on the range [0, 1], so for the comparison I moved the data accordingly. The distribution that's the closest match is actually the gamma distribution. With a ginormous α value (1110.2) but moved and scaled accordingly. I wanted to plot it but Desmos just bugged out - understandably so. Additionally, since gamma can only deal with variables > 0 we'd additionally have to move it. Let's discard that one since I just don't know how to deal with that. ^^" The next closest is the chi distribution with a k value of 137. Again scaled and moved to accordingly. Same problem, though less sever - let's discard it. This brings us to our 3rd and 4th place: The normal distribution and Student's t distribution. Both have pretty much the same probability value in the test. Looking at the parameters it's obvious why that is: The parameter v is 82104712197. Since the t-distribution converges to N(0,1) with v tending to infinity, we can effectively call them identical. Let's give the win to the normal distribution since the t distribution would need to be scaled and moved (again) and because of this ridiculous v value I can't plot it anyway (Damn you, Γ-function!). ^^ Let's take a closer look at the normal distribution: μ = 0.1829 σ = 1.5710 So the mean value is actually quite good, but the standard deviation is almost 60 % too big. Looking at our graphs we can see that the overall shape of the poll result (blue dots) is way to spread out to fit the target distribution N(0,1) (red), but fits reasonably well to our calculated distribution (green). The obvious exception being the point at x=0 which is noticeably favoured by the participants. That was fun. I should do something similar again some time. 😊 (📎1) RE: Can we approach a normal distribution with µ = 0 and σ = 1? Please share so we get a pretty graph. ^^"
Okay, analysis time, here we go! First of all, a short disclaimer: I'm by no means an expert. It has been years since my last statistics class and I hardly remember anything. So take everything with a grain of salt. 😅 My basic method for analysing the result was K-S (Kolmogorow-Smirnow) tests. Very un-scientifically I throw the data against a bunch of different known distributions and fit the parameters to the data (I think the `scipy` library uses MLE as the fitting method) to see which one matches the best. I didn't test any discrete distributions because honestly I couldn't get fitting to work and I didn't want to spend a bunch of time on that. Note: Our data is discrete, so the absolute K-S probability values are going to be tiny. But since we are only comparing them between each other it should be fine (again: This is not scientific, but just for fun. ^^). I tested the following distributions: normal, beta, cosine, semicircular, von Mises, chi, chi2, gamma, Student's t Some of these distributions only work on the range [0, 1], so for the comparison I moved the data accordingly. The distribution that's the closest match is actually the gamma distribution. With a ginormous α value (1110.2) but moved and scaled accordingly. I wanted to plot it but Desmos just bugged out - understandably so. Additionally, since gamma can only deal with variables > 0 we'd additionally have to move it. Let's discard that one since I just don't know how to deal with that. ^^" The next closest is the chi distribution with a k value of 137. Again scaled and moved to accordingly. Same problem, though less sever - let's discard it. This brings us to our 3rd and 4th place: The normal distribution and Student's t distribution. Both have pretty much the same probability value in the test. Looking at the parameters it's obvious why that is: The parameter v is 82104712197. Since the t-distribution converges to N(0,1) with v tending to infinity, we can effectively call them identical. Let's give the win to the normal distribution since the t distribution would need to be scaled and moved (again) and because of this ridiculous v value I can't plot it anyway (Damn you, Γ-function!). ^^ Let's take a closer look at the normal distribution: μ = 0.1829 σ = 1.5710 So the mean value is actually quite good, but the standard deviation is almost 60 % too big. Looking at our graphs we can see that the overall shape of the poll result (blue dots) is way to spread out to fit the target distribution N(0,1) (red), but fits reasonably well to our calculated distribution (green). The obvious exception being the point at x=0 which is noticeably favoured by the participants. That was fun. I should do something similar again some time. 😊 (📎1) RE: Can we approach a normal distribution with µ = 0 and σ = 1? Please share so we get a pretty graph. ^^"
Okay, analysis time, here we go! First of all, a short disclaimer: I'm by no means an expert. It has been years since my last statistics class and I hardly remember anything. So take everything with a grain of salt. 😅 My basic method for analysing the result was K-S (Kolmogorow-Smirnow) tests. Very un-scientifically I throw the data against a bunch of different known distributions and fit the parameters to the data (I think the `scipy` library uses MLE as the fitting method) to see which one matches the best. I didn't test any discrete distributions because honestly I couldn't get fitting to work and I didn't want to spend a bunch of time on that. Note: Our data is discrete, so the absolute K-S probability values are going to be tiny. But since we are only comparing them between each other it should be fine (again: This is not scientific, but just for fun. ^^). I tested the following distributions: normal, beta, cosine, semicircular, von Mises, chi, chi2, gamma, Student's t Some of these distributions only work on the range [0, 1], so for the comparison I moved the data accordingly. The distribution that's the closest match is actually the gamma distribution. With a ginormous α value (1110.2) but moved and scaled accordingly. I wanted to plot it but Desmos just bugged out - understandably so. Additionally, since gamma can only deal with variables > 0 we'd additionally have to move it. Let's discard that one since I just don't know how to deal with that. ^^" The next closest is the chi distribution with a k value of 137. Again scaled and moved to accordingly. Same problem, though less sever - let's discard it. This brings us to our 3rd and 4th place: The normal distribution and Student's t distribution. Both have pretty much the same probability value in the test. Looking at the parameters it's obvious why that is: The parameter v is 82104712197. Since the t-distribution converges to N(0,1) with v tending to infinity, we can effectively call them identical. Let's give the win to the normal distribution since the t distribution would need to be scaled and moved (again) and because of this ridiculous v value I can't plot it anyway (Damn you, Γ-function!). ^^ Let's take a closer look at the normal distribution: μ = 0.1829 σ = 1.5710 So the mean value is actually quite good, but the standard deviation is almost 60 % too big. Looking at our graphs we can see that the overall shape of the poll result (blue dots) is way to spread out to fit the target distribution N(0,1) (red), but fits reasonably well to our calculated distribution (green). The obvious exception being the point at x=0 which is noticeably favoured by the participants. That was fun. I should do something similar again some time. 😊 (📎1) RE: Can we approach a normal distribution with µ = 0 and σ = 1? Please share so we get a pretty graph. ^^"
Nice ! Any idea why the average is so close to 0, and the symmetry is so well balanced ?
After all there is no reason that as many users chose positive and negative values, and that more users chose 0 than any other value ! Unless many people "cheated" and decided their answer by actually using the output of a normal law, which I guess 99% of users are too lazy/unable to do.
So, is it sheer miracle that a bell shape is actually found ? ?
You are lucky 🍀 now it’s closed it’s a pretty pretty graph 😍
Okay, analysis time, here we go! First of all, a short disclaimer: I'm by no means an expert. It has been years since my last statistics class and I hardly remember anything. So take everything with a grain of salt. 😅 My basic method for analysing the result was K-S (Kolmogorow-Smirnow) tests. Very un-scientifically I throw the data against a bunch of different known distributions and fit the parameters to the data (I think the `scipy` library uses MLE as the fitting method) to see which one matches the best. I didn't test any discrete distributions because honestly I couldn't get fitting to work and I didn't want to spend a bunch of time on that. Note: Our data is discrete, so the absolute K-S probability values are going to be tiny. But since we are only comparing them between each other it should be fine (again: This is not scientific, but just for fun. ^^). I tested the following distributions: normal, beta, cosine, semicircular, von Mises, chi, chi2, gamma, Student's t Some of these distributions only work on the range [0, 1], so for the comparison I moved the data accordingly. The distribution that's the closest match is actually the gamma distribution. With a ginormous α value (1110.2) but moved and scaled accordingly. I wanted to plot it but Desmos just bugged out - understandably so. Additionally, since gamma can only deal with variables > 0 we'd additionally have to move it. Let's discard that one since I just don't know how to deal with that. ^^" The next closest is the chi distribution with a k value of 137. Again scaled and moved to accordingly. Same problem, though less sever - let's discard it. This brings us to our 3rd and 4th place: The normal distribution and Student's t distribution. Both have pretty much the same probability value in the test. Looking at the parameters it's obvious why that is: The parameter v is 82104712197. Since the t-distribution converges to N(0,1) with v tending to infinity, we can effectively call them identical. Let's give the win to the normal distribution since the t distribution would need to be scaled and moved (again) and because of this ridiculous v value I can't plot it anyway (Damn you, Γ-function!). ^^ Let's take a closer look at the normal distribution: μ = 0.1829 σ = 1.5710 So the mean value is actually quite good, but the standard deviation is almost 60 % too big. Looking at our graphs we can see that the overall shape of the poll result (blue dots) is way to spread out to fit the target distribution N(0,1) (red), but fits reasonably well to our calculated distribution (green). The obvious exception being the point at x=0 which is noticeably favoured by the participants. That was fun. I should do something similar again some time. 😊 (📎1) RE: Can we approach a normal distribution with µ = 0 and σ = 1? Please share so we get a pretty graph. ^^"