Hello，I noticed that you are using T-tests for the conversion rate A/B testing with frequentist statistical methods. Why not use a Z-test?

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Hey, there - I'll pose this question to our data science team and get back to you!

Thanks

Hi there, I was able to chat with our Lead Data Scientist and he passed along the following: One should usually never use a z-test if you can use a t-test. The difference between which test to choose has to do with whether you know the population variance or whether you're estimating it. In practice, we're always estimating it and a t-test is consequently more appropriate. The difference between the 2 tests disappears for basically any meaningful, online A/B test.

thanks