Hacker News new | ask | show | jobs
by an_d_rew 887 days ago
> different observers with different priors can come to radically different conclusions

One may view this as a feature, not a bug! :-) To quote Jaynes, "there is no unique notion of ignorance". And to further quote Carl Sagan, "extraordinary claims require extraordinary evidence".

Combining these two statements, if Alice expects an experiment to succeed and Bob expects it to fail, each very well MAY come to different conclusions after observing the result, depending on the depth of their prior belief.

This is completely normal in how everyday science is carried out. Even informally... how many researchers had grants denied funding because the funding agency had a prior belief that the subject of the grant had a foregone conclusion? The opinions (the prior) of the grant panel differ markedly from the grant applicant, and each would require correspondingly different levels of proof from any subsequent experiment!

1 comments

So what makes 'Bayesian math' meaningful to anyone who is not Alice or Bob?

It just seems like random speculations to any outside observer. Whether they are claimed to be caused by a coincidental pattern of neurons firing, 'math', etc., seems irrelevant.

A lot of the time you could say that it's structured handwaving, but the structure gives you a number of benefits over regular handwaving ;)

Pretty quickly we can tell if we disagree about the whole framing of something (the overall model) or our priors are just very different.

The explicitness of priors is a big feature and when they're wildly different we can discuss / present evidence for those.

We can also see how much our priors matter in terms of outcome, i.e, what are the "load bearing beliefs" that lead us to make a certain prediction.

How does this lead to something that will convince a random third party, outside of Alice and Bob, in a way that can be uniquely identified as 'Bayesian math'?
How random is the third party? What epistemic frameworks do they find acceptable? (sorry if I am not getting what you are asking).

A theological argument (no matter how good) is unlikely to convince an atheist of anything.

In a perfect world if we agree that bayesian epistemology makes sense and I accept your priors and your model then I should be willing to accept your conclusions. But because of bounded rationality and other factors like https://slatestarcodex.com/2019/06/03/repost-epistemic-learn... then I might still refuse to do so if your conclusions are ludicrous or repugnant to me :)

> How random is the third party? What epistemic frameworks do they find acceptable?

Any of the 8 billion people, who are not Alice and Bob, passing by... who, largely, don't even care about the concept of 'epistemic frameworks' in the first place.

Writing an explanation that only is convincing if the reader already believes in 'Bayesian Math' in the first place seems redundant, hence me pointing it out.

Right, but I don't feel this is a problem with bayesian reasoning.

If you want to _convince_ people you are in the domain of psychology, focus groups, marketing, social engineering etc.

An argument being convincing is not the same as an argument being valid.