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It’s Hard to Get A/B Testing Right

Posted on:Aug 13, 2022

I was sitting as a spectator in an open design review during my time at Amazon. One of the teams had written a 6-pager doc on a new recommendation system. To test it out, they wanted to send an email to a random set of users with products recommended by the new system and see how many of them convert. Looked good to me. Then one senior person commented:

“This will test the effect of sending one new email to users, and not necessarily your recommendation system. Pick another set of users and send them an email in the same format with random and best-selling products.”

The presenter admitted they hadn’t thought of that. It made total sense. I was stunned as well. First, with the ease that the senior person was able to point out the flaw (so this is what experience looks like!). And second, with the importance of feedback.

I extend this to comparing your life and goals with anyone else on Earth-616. Let’s say you see a post by someone claiming they value X over Y. You might be tempted to think that the only variable that is different between them and you is the thought process. Not true. They might have a safety net. Do you? You might have a large social media following. Do they? They might have gone through a life-changing experience. Have you? You might have a retirement fund in the bank. Do they? Think thoroughly. Get your comparisons reviewed by fresh pair of eyes.