Karsten Bräckelmann wrote: > On Fri, 2009-10-02 at 00:08 +0200, mouss wrote: >> Karsten Bräckelmann wrote: >>> False positive. Something, that matches (positive) the criterion for a >>> certain test, but should not (false). > > I stand to what I said. >
I'm not surprised:) >> you can certainly devise a system to detect alpha(foo) where alpha is a >> function mapping a Banach space to a Hilbert Space, and define what FP, >> FN, FX mean in the context you consider. you can also say "let PI=69, >> ... ". but conventions are here for a reason. they allow us to >> understand each others more easily. the fact that children of today can >> solve computation problems that "great scientists" of the old times >> couldn't handle is thanks to conventions (think of a/b * c/d = >> (a*c)/(b*d), which looks trivial today, but wasn't before). >> >> when talking about spam or intrusion detection, FN means "missing" and >> FP means "false alarm". if we allow defining FN and FP differently, then >> we'll need to rewrite a lot of books, reports, articles, ... > > IFF you are talking about the black box that spam detection is, that is > true. > > If you are talking about a rule like FORGED_MUA_OUTLOOK, it appears to > be that simple. However, it is not. You are looking at a single test, > which -- if positive -- either is correct or wrong. > I understand the rationale, but I find this too abstract for "common" discussions. > Same for RCVD_IN_DNSWL. If it positively matches, it either it is > correct, or wrong. A false positive is a match, that is wrong. No matter > the score you assign the test. > except that it depends what the test really means. dnswl doesn't mean the listed hosts never send spam. I am happy that it lists debian list servers, Orange, ... etc. > > This concept is NOT specific to spam detection, or even computer > science. As a matter of fact, when I first really grasped the concept, a > medical scientist explained it to me. > now that you say it, this is true. I too believ that medical science has precedence in this area. > Yes, a FP for a rule that identifies *ham* actually evaluated positive > on a spam. It only appears to be spam centric on this list, cause it is > mainly dedicated to identifying spam, not ham. > > You might want to ask wikipedia as well. And don't focus on the spam > filtering *example*, which again exclusively talks about a rule > identifying spam. Not ham. > my point was that in a spam oriented forum, the meaning of some words is what "most of us" (yes, this is hard to define) think they mean. the principle of least astonishment. anyway, I'm sorry for bringing the discussion to this sand. so I will stop here (of course, offlist is ok for any discussion, including garbage without collection:)
