4 ms·
> If clinical trialists use p-values wrong, how is moving to Bayesian methods going to be less misused and misunderstood? Bayesian methods have the advantage t
by stdbrouw 10y ago
> If clinical trialists use p-values wrong, how is moving to Bayesian methods going to be less misused and misunderstood?
Bayesian methods have the advantage that, while they can still be misused and misunderstood, at least when used correctly they tell us what we want to know and are easy to interpret (a posterior probability is exactly what you think it is) whereas p-values are hard to interpret correctly (a low p-value can imply a large effect size, a large sample size, or in the face of publication bias, lord knows what).
That said, I do think that the advantage to Bayesian thinking in research would mostly not be about the methods but about the attitude: aside from a couple of weirdos pushing Bayes factors, Bayesian statisticians almost universally communicate results using credible intervals (HPD) instead of dichotomizing the evidence into significant or not significant. Frequentist confidence intervals will get you most of the way there and could completely replace p-values, but if you're going to advocate for better statistics and uproot established practices, might as well go all the way and encourage better methods and better ways of communicating results at the same time.
- jamii 10y agohttp://pcl.missouri.edu/sites/default/files/freeLunch_0.pdf http://pcl.missouri.edu/sites/default/files/freeLunch_0.pdf has a neat example of why Bayes factors might be preferred over credible intervals. > By using posterior credible intervals, we might reject the null, but by using Bayes’ rule directly we see that this rejection is made prematurely as there is no decrease in the plausibility of the zero point.
- stdbrouw 10y agoBut that's the thing, there is just never any real need to do hypothesis testing, the range of plausible effect sizes is all that matters.
- conjectures 10y agoI see what you're saying and mostly agree, but... This could totally come up if you have a non factorising multivariate posterior distribution, and you want some sound way to summarise it when you can't reason from the marginals alone.