This is a case where I wouldn’t use Bayes’ theorem. You have to estimate some probabilities directly, using your experience and knowledge, and P(A|B) (the probability that they are interested in you given that they bought you a drink) seems easier to estimate directly than some of the other probabilities which you would have to estimate to calculate P(A|B). For instance, if many people have bought you drinks before, you could just consider what proportion of them were interested in you. Or, you could rely on drink-buying that you’ve observed, or just cultural knowledge. On the other hand, I don’t know how I’d estimate P(A) (the prior probability that a person is interested in you).
That’s really interesting, because I feel almost the opposite way. Estimating P(A) is easy, there are many factors I can look at, and I have experience with it. However, I don’t have a lot of experience with people buying me drinks for various reasons, so I’m not sure how to update on that just from experience.
It’s actually quiet possible that the magnitude of error I have in my estimations/assumptions renders them useless, but, even then, the exercise overall is pretty helpful to understand Bayes’ theorem better.
This is a case where I wouldn’t use Bayes’ theorem. You have to estimate some probabilities directly, using your experience and knowledge, and P(A|B) (the probability that they are interested in you given that they bought you a drink) seems easier to estimate directly than some of the other probabilities which you would have to estimate to calculate P(A|B). For instance, if many people have bought you drinks before, you could just consider what proportion of them were interested in you. Or, you could rely on drink-buying that you’ve observed, or just cultural knowledge. On the other hand, I don’t know how I’d estimate P(A) (the prior probability that a person is interested in you).
That’s really interesting, because I feel almost the opposite way. Estimating P(A) is easy, there are many factors I can look at, and I have experience with it. However, I don’t have a lot of experience with people buying me drinks for various reasons, so I’m not sure how to update on that just from experience.
It’s actually quiet possible that the magnitude of error I have in my estimations/assumptions renders them useless, but, even then, the exercise overall is pretty helpful to understand Bayes’ theorem better.