-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hi
On Wednesday 7 January 2015 at 4:14:53 PM, in <mid:f4a4690a-84e9-4a09-b32d-7afc98339...@sixdemonbag.org>, Robert J. Hansen wrote: > One more thing — remember that probabilities are > tricksy things. They vary wildly depending on how one > looks at the problem. A lot of statistical analysis throws up pretty non-intuitive answers. Like how few random people you need in a room before there are probably two who share a birthday. > Let’s say there are 10,000 threats of murder that are > made, and only 10 murders. If we assume that only ten > of those 10,000 threats was connected to a murder, the > probability of any given threat being connected to a > murder is vanishingly small — one in a thousand, or > 0.1%. Starting from the fact there was a threat, it > would be foolish to conclude the speaker intended on > murdering someone. That is how I was looking at it. > However, if we look at the murders, we discover that > 100% of them are connected to threats. 100% seems unlikely, but it is probably pretty high. > If you start > from a murder, it would be pretty wise to start looking > into who threatened the person. Fair enough. > If the only fact you have is “Alice threatened Bob’s > life,” then yes, that’s pretty poor evidence on which > to investigate Alice for Bob’s death. But if the facts > you have are “Alice threatened Bob’s life and Bob was > killed under suspicious circumstances,” then yes, > that’s actually pretty good evidence on which to > investigate her. Obviously, without Bob's suspicious death there would be no reason to investigate Alice. And there could be hundreds of people who recently uttered a throwaway threat at Bob. > ObComputerSecurityStuff: this turns out to be a recurring > mathematical pattern that pops up all over in computer security. If > you have 10,000 IDS red-flags warning of catastrophe and catastrophe > never happens, that’s a pretty bad system… but if in post-incident > analysis you discover, “hey, IDS correctly reported this when it was > happening,” Management will ask you some really harsh questions > about why you didn’t pay attention to the warnings. A warning system with many false positives is no warning system at all. - -- Best regards MFPA mailto:2014-667rhzu3dc-lists-gro...@riseup.net Colourless green ideas sleep furiously (Noam Chomsky) -----BEGIN PGP SIGNATURE----- iQF8BAEBCgBmBQJUrlFPXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXRCM0FFN0VDQTlBOEM4QjMwMjZBNUEwRjU2 QjdDNzRDRUIzMUYyNUYwAAoJEGt8dM6zHyXw4esH/2AjMDHVSPFMih02h6r4IisO a/cTJG3LPnMMrr88hDlJ902PP/vhciEx4qI3Focvq4Q4jS/jQ4kuJKrM12fRVZOm WiSL3gsvlOzGIC3zuOOpRa08WiqEPd82nttbi8e60S65eBKBYCNDxRtUifidwK9w +Nmn0Fb5C53W7qI/vfdq0wpIdxMsA/WZAJQCXkSU4Kc0kEfnsiegOdaadHDe8YJB j9ZbpidErk/h7wVAkNDg/0nlhxLGHeBi90Fd8J4oqOtBlGFElkYa2VNCspkXnWP7 FpK/MkvS+GjsJYIa+mBOLYxeanLHqJvibU9/HyzUlMu2hFM2Dix9pg2qL+J4DB2I vgQBFgoAZgUCVK5RVF8UgAAAAAAuAChpc3N1ZXItZnByQG5vdGF0aW9ucy5vcGVu cGdwLmZpZnRoaG9yc2VtYW4ubmV0MzNBQ0VENEVFOTEzNEVFQkRFNkE4NTA2MTcx MkJDNDYxQUY3NzhFNAAKCRAXErxGGvd45HR0AQBpXYQvhfBZYtAaSTueWissr/r0 ieadHCWdlVz4eAOs+QEAuXQG+p7qeyrJ32faHphTV7G2Pv/EPXG2q/jsgdp15g4= =Gi3x -----END PGP SIGNATURE----- _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
