Comment on Advancing Certainty

Mon, 18 Jan 2010 20:23:03 GMT

I am strongly tempted to defy the data here.

In fact, looking at the blog, I didn't find much data. There was a link to an unimpressive article by a psychoanalyst, with some not-particularly-expert-sounding comments from the blog author -- who also admitted to not being able to tell whether Knox was lying during the testimony without hearing the questions. Furthermore, the author's understanding of the facts of the case left a lot to be desired, to put it mildly.

But even if we grant that this person has a tested above-average ability to identify characteristic signs of lying/sociopathy, and has identified Knox as possessing some of these signs (an assertion I didn't actually find, though I could have missed it), I'd want to know a lot more: what sort of likelihood ratios are we talking about? (I.e. what fraction of non-sociopaths also exhibit these signs?) Exactly what is this person's error rate? What do other "wizards" say in independent testing with strict experimental protocols? Etc.

Then there's also the theoretical question: if this evidence is truly worth paying attention to, why shouldn't it be admissible in court? (Presumably there's no danger of abuse of police power or similar, so the reason for exclusion must have to do with the evidentiary strength or lack thereof.)

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