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Flip a coin 50 times and get 50 heads, it's almost impossible it's a fair coin. Does your BetaDist function work in that case?
by isostatic 9y ago
Flip a coin 50 times and get 50 heads, it's almost impossible it's a fair coin. Does your BetaDist function work in that case?
- joshuamorton 9y agoNo, the beta distribution BetaDist[a, b] is only defined for a, b strictly > 0. When a or b is very large and the other is zero, you can treat it as 1 and get a decent approximation, but it'll be a an estimate that biases towards the center.
- joshuamorton 9y agoI should also mention that if you're willing to make assumptions like a uniform prior, this totally works, but it can lead to some surprising results for small a, b. Notably a uniform prior is Beta[1, 1]. Beta[2,1] implies something like a 75% chance of the true mean being above .5, which seems a tad overzealous.