On Jun 30, 2007, at 6:29 PM, Loren Wilton wrote:


And after typing all this I'm thinking you might be right. But part of this approach is to run all these rules in YES/NO fashion and see if the probability is significant. For example: If I tested for SOME_TEST=NO and found it was scoring a probability of ~0.500 then it's indisputable that you are right.

Well, this still doesn't make any real sense to me; it seems equivalent to the attempts at bayes poison that spammers stick into their spams: a bunch of words totally unrelated to the mail in the hopes of outweighing the useful terms. Now their trick works as a good spam indication because the words they pick aren't common to my ham mails, so it is really a good spam indication rather than poison. I'm not immediately convinced that will hold for the usage you intend. Maybe. Maybe not.

However, if you want to do this, remember that bayes works on tokens and has a tokenizer. So SOME_RULE=YES is probably either two or three tokens, and you will end up scoring on the probability of YES and NO, along with the frequency of the rule names, which will be 1. So you probably want to do NO_SOME_RULE and YES_OTHER_RULE or the like when you build the insert list. Again though I'm not sure I see the point in the yes and no factors; the presence or absense of a word in the mail seems like a pretty good yes/no indication to me.

Were I doing it I'd try it both ways and see if there is any difference in results.

I agree with you that it's probably not going to be very effective to use a binary token (eg: SOME_RULE=YES vs SOME_RULE=NO) compared to the presence of the rule (SOME_RULE exists implies SOME_RULE=YES).

So the method:
       $list = $status->get_names_of_tests_hit ()
may cover everything that is required to evaluate this approach.

Unfortunately I'm not on the SpamAssassin Bayes modules -- I wrote my own Bayes Engine because I wanted to do that and then thought about including the Rules results from SpamAssassin. I don't know where this might be going, but it seems to be working extremely well for me based on a training set of just a couple hundred emails in total.

Reply via email to