4 ms·

Hi Mike! :-) Thanks for the kind words. I don't know much about atmospheric science, but the canonical "real" example of Bayesian reasoning is a diagnostic t

by lisper 4y ago

Hi Mike! :-) Thanks for the kind words. I don't know much about atmospheric science, but the canonical "real" example of Bayesian reasoning is a diagnostic test for some disease, where you are told that X% of the population has the disease, where X is typically a small number, so the "surprising" result is that your odds of having the disease are low even if you test positive and the test is generally accurate. The problem is: how can you possibly know what percentage of the population has the disease? To determine that you'd need a reliable test, but there is no such test. That's the whole point! If there were a 100% reliable test you wouldn't need to do any math.

mturmon 4y ago
Sometimes called the "Bayesian dogma of precision" -- to any state of nature, you can assign a crisp probability (e.g., https://sipta.org https://sipta.org). For your disease example -- if you don't know the accuracy of the test ("the model"), and/or if you can't figure out what percent of the population has the disease ("the prior"), then you can't turn the Bayesian crank. Yet, some do, because Bayesian good.