So, komponisto, Kevin, Pavitra, or anyone else, any general thoughts on how to calculate p(K | guilt) or p(K | innocence)?
Elsewhere, I described my reasoning on p(K | innocence) as follows:
Start, per Ghirga, with approximately 33% probability, or 1:2 odds. Then update on the fact that Amanda and Raffaele are factually innocent; this takes me upward to about the level of total ignorance, 50%, or 1:1 odds. By Bayes’ theorem this implies that I must think that innocence is twice as likely in the case of acquittal as in the case of conviction. I think that’s a reasonable, even conservative, estimate for a judicial system that is supposed to have some connection with reality. (Some may want to scoff at the notion that this accurately describes Italy’s system, but rhetoric doesn’t win bets!) Upon the granting of the DNA review in December I updated slightly to 60% (3:2 odds), implying that I think this was 1.5 times as likely to happen in an acquittal-world as in a conviction-world. (Which again strikes me as kind of conservative.) Now that we have the results, I’m at 80%, or 4:1 odds; to have gotten there from 3:2, I must have thought that this result was 8⁄3 (about 2.67) times more likely under the assumption of eventual acquittal than under the assumption of re-conviction.
Elsewhere, I described my reasoning on p(K | innocence) as follows: