Michael Tobis wrote: > I'm at a conference with some statisticians at this moment. One talk > today discussed a recent paper in Nature which alleged that the > Chixculub meteor had a certain origin with probablity 90%. The gist of > the talk was that the professional statistician was unable to ascribe > enough meaning to the 90% claim to refute it.
http://www.nature.com/nature/journal/v449/n7158/full/nature06070.html The paper itself is actually clear enough. If a particular event took place as described, then it would have produced impacts at a much greater rate than the background, such that any impact would with 90% probability come from this event. I don't think it is unreasonable to think about a single impact as a random sample from an "urn" of rocks floating around in space. But on the face of it the research does not justify the claims made in the press (or your phrasing above). > Global change isn't a drug trial and we can't round up 500 planets to > give half of them CO2 and half a placebo to get a 99% refutation of > the null hypothesis. We actually have to think, not just apply > formulas. What I find interesting about it all is how little people care. It's not as if I am the first person to think about it, indeed I am doing nothing more than following a well-worn path (there are rants aplenty on this general topic on the web). And yet...as Nature put it, "the concerns you have raised apply more generally to a widespread methodological approach" and therefore can safely be ignored. James --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
