No, the intercept for the logistic (odds of the biomarker being expressed in the reference state was Logistic(0,1), while the prior on the odds ratio of B v.s. A was a mixture of a logistic and a normal.

The gory details are here:

http://statmd.wordpress.com/2013/11/26/the-little-non-informative-prior-that-could-be-informative/

A shot: Rougly dnorm(mu = 0, sigma = 2)?

]]>And, do you see the point of “I think the authors over-extended thier technical abilities just to get the paper published.”?

Perhaps the paper is not revolutionary, but it appears to contain sensible recommendations, as you mention. Also, the statistical literature is full of misuses of “noninformative” and “vague” priors. Therefore, a paper containing some simple guidelines helps more than it hurts.

]]>X: Could you be more explicit as I do not get the point of this comment? iX

]]>Quite a strong claim, you may want to look at the aims and scope of the journal.

Anyway, the point of the paper is to set “noninformative priors” on the quantities of interest, not just flat priors on the parameters …

]]>Of course the methods section in the journal will read something like: “we used non-informative priors to model our prior beliefs for the detectability of the biomarker in Condition A and B” (a true statement), yet these priors look pretty darn informative in the log-odds scale. (JAGS and BUGS samplers worked much better as an added bonus)

I think Keith’s journal experience shows we have a long way to go before we accept that the word “non-informative” is misleading and that a very useful line of research for us doing applied Bayesian analyses is exactly the priors induced through transformations of parameters.

I could even go so far to suggest to Keith to try one of the Epidemiology Journals (or even Stat Med) as a venue for him to disseminate this sort of research because it is of immense practical importance.

]]>thanks: what you show here is that it is very rare to be in a state of complete and absolute ignorance and thus that with the focus on entities one can build intuition about, it is manageable to get mildly informative priors….

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