Hi guys! I had a doubt the other day about computing the average of CTR, when the observed unit is a user. 1. Should I compute the avg. CTR per user, instead of (all Clicks) / (all Impressions)? To maintain the units independency; 2. Should I compute the harmonic mean instead of the aritmethic mean, since i'm averaging rates?

Currently in GrowthBook, the only thing we support is what you suggest in #1, average CTR per user. We are going to add support for true ratio metrics with proper variance correction soon. I'm not too familiar with harmonic means, so not sure on that part of your question.

Ohh great, that's interesting About the harmonic mean, i was confounded with another situation, sry 😛