# Realistic (Math 1)

https://arbital.com/p/bayes_examples_realistic_math1

by Eliezer Yudkowsky Feb 8 2016 updated Feb 27 2016

Real-life examples of Bayesian reasoning

### What's the chance that a potentially good partner would flake on the first date?

From a test subject for an early version of the Bayes intro:

A 96% OKCupid match canceled their first date for coffee without providing an explanation.

She estimated that a man like this one had prior odds of 2 : 5 for desirability vs. undesirability, based on his OKCupid profile and her past experience with 96% matches. She then estimated a 1 : 3 likelihood ratio for desirable vs. undesirable men flaking on the first date. This worked out to 2 : 15 posterior odds for the man being undesirable, which she decided was unfavorable enough to not pursue him further.

She used this explicitly Bayesian calculation to interrupt a 'worrying' cycle wherein she was focusing on one consideration, then a different consideration, arguing for pursuing further / not pursuing further. Making up numbers and doing the Bayesian calculation terminated this cycle.