▲ | stared 7 hours ago | |
I think we should declare a moratorium on the use of p-values. If you don't understand what a p-value is, you shouldn't use it. If you do understand p-values, you're probably already moving away from them. The Bayesian approach makes much more sense. I highly recommend David MacKay's "Information Theory, Inference and Learning Algorithms," as well as "Bayesian Methods for Hackers": https://github.com/CamDavidsonPilon/Probabilistic-Programmin.... At the same time, startups aren't science experiments. Our goal is not necessarily to prove conclusively whether something is statistically "better". Rather, our goal is to solve real-world problems. Suppose we run an A/B test, and its result indicates B is better according to whatever statistical test we've used. In this scenario, we will likely select B—frankly, regardless of whether B is truly better or merely indistinguishable from A. However, what truly matters in practice are the metrics we choose to measure. Picking the wrong metric can lead to incorrect conclusions. For example, suppose our data shows that users spend, on average, two more seconds on our site with the new design (with p < 0.001 or whatever). That might be a positive result—or it could simply mean the new design causes slower loading or more confusion, frustrating users instead of benefiting them. |