HHammond/kcbo — pull request #2 by cwharland (2014-08-08 22:07:34+00:00)
Title: added alpha and beta params for beta-binomial

Added alpha and beta as parameters for beta-binomial. It's useful in display advertising to vary this parameter due to the extremely low conversion rates (using beta 2,2 for example for something more related to bernoulli trial).

I'm a horrible production code writer so feel free to suggest changes to my code in the pull request =)

I tested this with varying the parameters for two highly imbalanced groups (90%/10% a/b test) with 0.01% ctr rates and the parameters behave as expected.