Estimating the chances of something that hasn’t happened yet
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Re: Estimating the chances of something that hasn’t happened yet
#2I’m not very good at maths, so I didn’t understand the whole post. However, does the size of the whole population affect the “3/n” thing? For example, if I’ve read 200 pages of a 201 page book and not discovered a typo the chances are 3/200 if I’ve understand the post correctly. If the book has 20000 pages, is the probability still 3/200?
Re: Estimating the chances of something that hasn’t happened yet
#3I’m not very good at maths, so I didn’t understand the whole post. However, does the size of the whole population affect the “3/n” thing? For example, if I’ve read 200 pages of a 201 page book and not discovered a typo the chances are 3/200 if I’ve understand the post correctly. If the book has 20000 pages, is the probability still 3/200?
N is the sample size that you’ve sampled already in your observation.
If you’ve sampled all the pages, then we are talking about certainty which this wouldn’t apply.
Re: Estimating the chances of something that hasn’t happened yet
#4There's a trivial corollary, which I remember from my first physics class. Never base anything on less than three measurements. Or maybe it wasn't even physics, but rather carpentry. The old "Measure twice, cut once." rule is iffy.
Re: Estimating the chances of something that hasn’t happened yet
#5I’m not very good at maths, so I didn’t understand the whole post. However, does the size of the whole population affect the “3/n” thing? For example, if I’ve read 200 pages of a 201 page book and not discovered a typo the chances are 3/200 if I’ve understand the post correctly. If the book has 20000 pages, is the probability still 3/200?
N is the sample size that you’ve sampled already in your observation. If you’ve sampled all the pages, then we are talking about certainty which this wouldn’t apply.
In my example, there’s either 1 page or 19800 pages left. But the post suggests the probability of a typo is the same in both cases.
Re: Estimating the chances of something that hasn’t happened yet
#6Interesting: the frequentist derivation is using the logarithm, while the Bayesian one, the exponent.
Re: Estimating the chances of something that hasn’t happened yet
#7Earlier quoted context omitted.
N is the sample size that you’ve sampled already in your observation. If you’ve sampled all the pages, then we are talking about certainty which this wouldn’t apply.
In my example, there’s either 1 page or 19800 pages left. But the post suggests the probability of a typo is the same in both cases.
It's the probability of finding a typo on a page, not the remainder of the book.
Re: Estimating the chances of something that hasn’t happened yet
#8I’m not very good at maths, so I didn’t understand the whole post. However, does the size of the whole population affect the “3/n” thing? For example, if I’ve read 200 pages of a 201 page book and not discovered a typo the chances are 3/200 if I’ve understand the post correctly. If the book has 20000 pages, is the probability still 3/200?
> It says that if you’ve tested N cases and haven’t found what you’re looking for, a reasonable estimate is that the probability is less than 3/N.
So in your example, according to the rule, the probability of errors is less than 3/200. Which it is, either 0/201 or 1/201.
Re: Estimating the chances of something that hasn’t happened yet
#9I’m not very good at maths, so I didn’t understand the whole post. However, does the size of the whole population affect the “3/n” thing? For example, if I’ve read 200 pages of a 201 page book and not discovered a typo the chances are 3/200 if I’ve understand the post correctly. If the book has 20000 pages, is the probability still 3/200?
After 200 pages you could estimate the probability that the next PAGE has a typo. You could use the number of pages left in the book to estimate how many pages may have typos.
Re: Estimating the chances of something that hasn’t happened yet
#10There's a trivial corollary, which I remember from my first physics class. Never base anything on less than three measurements. Or maybe it wasn't even physics, but rather carpentry. The old "Measure twice, cut once." rule is iffy.
Three data points is not the same thing as three measurements of the same object.