Philip Stark of UC Berkeley is the frequentist in question. I pointed him to this discussion and he replied as follows (forwarded with his permission).
mt ---------- Forwarded message ---------- From: Philip B. Stark <...> Date: Sep 13, 2007 1:24 PM Subject: Re: frequentism discussion Hi Michael-- Thanks for pointing me to this and for your interest. My argument--applied to earthquake forecasts by the USGS--is in this preprint: http://statistics.berkeley.edu/~stark/Preprints/611.pdf Slides from Monday's talk are here (in OpenOffice format): http://statistics.berkeley.edu/~stark/Seminars/sandia07.odp My points about the frequentist coverage probability of Bayesian credible regions were not connected to the Chicxulub story... Luis and I are planning to write something up for the conference volume on that topic. The gist of my argument about whether the chance the KT impactor came from Baptistina Asteroid Family is that the probability ultimately comes from stochastic assumptions about the collision that formed the BAF (Gaussians for some things, truncated Gaussians for some things, uniform for others, etc.), simplified simulations about how orbits evolve to move objects into the resonances with Jupiter and Mars, how objects are ejected from resonance, and on and on, plus ad hoc corrections to astronomical catalogs, extrapolation of empirical scaling laws well beyond the data, assumptions that things like albedo, density and specific heat capacity are constant, etc. There's a huge chain of physical and probabilistic assumptions comprising an extremely complex--and tenuous--model. Buy the model, buy the 90% figure. But why buy the model? This is not like an urn model, and my skepticism is not because this is a one-off event, or even that it either happened or didn't. (We could rephrase it to be prospective, rather than retrospective, and I'd have much the same problem with it.) My main complaint is that the model is far fetched and only weakly tied to observation. Best wishes, Philip On Thu, 2007-09-13 at 12:47 -0500, Michael Tobis wrote: > There's an interesting discussion of reasoning under uncertainty on a > public discussion list which I manage. I mentioned the Chixculub > argument you presented at the Santa Fe workshop and that has proved an > anchor of the discussion. > > However, I am doing a lousy job of defending your position because of > some combination of not understanding it and/or not agreeing with it. > So far nobody else has showed up to advocate for a frequentist > perspective. > > You may at least be interested in reading the discussion so far. Your > input would be most welcome. > > http://groups.google.com/group/globalchange/browse_thread/thread/cd703ecce94de4d4 > > regards > Michael Tobis > http://www.ig.utexas.edu/people/staff/tobis/ -- Philip B. Stark | Professor of Statistics | University of California Berkeley, CA 94720-3860 | 510-642-1430 | www.stat.berkeley.edu/~stark --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
