> -----Original Message----- > From: Gary Funck [mailto:[EMAIL PROTECTED] > Sent: January 10, 2004 3:29 PM > To: [EMAIL PROTECTED] > Cc: Spam Assassin Dev; [EMAIL PROTECTED] (Henry Stern) > Subject: RE: Neural Net scoring > > Thanks. Here's the link: > http://bugzilla.spamassassin.org/show_bug.cgi?id=2910 > > This looks interesting. I echo Sidney's follow-up: > > "That's impressive. How close are the results to those of the GA? That's > actually two questions: 1) How close is the scoring that the perceptron > comes up with to the scoring that the GA comes up with? and 2) How much > difference in spam categorization results is there between using the > scores generated by the perceptron and those generated by the GA?"
Some of the scores are the same, others are different. The GA has some added constraints that are required because it works on a global level (it looks at mean performance of solutions over the training set) where stochastic gradient descent looks at performance on individuals. > This approach looks like it does a good job of mixing some of the benefits > of a the current additive scoring approach and a Neural Net. The final > neural > net that is derived is much simpler than a full-fledged net, but it has > the > advnatage of being simple to understand, and maps well onto the existing > framework. The current additive scoring approach is precisely equivalent to a perceptron with a linear transfer function and a threshold activation function. What I do is use a different activation function for training (threshold activation functions are discontinuous and therefore not differentiable) and then map the results to a threshold perceptron. > It would've been interesting to see what sorts of scores this approach > produced, > and how well they worked in practice. (There's also a question of > copyright > that > would need to be resolved for this approach to gain wider use.) Once the preprocessing stuff is worked out, I'll write a white paper that discusses the results in detail. As for copyright, I've signed an Apache CLA. Henry ------------------------------------------------------- This SF.net email is sponsored by: Perforce Software. Perforce is the Fast Software Configuration Management System offering advanced branching capabilities and atomic changes on 50+ platforms. Free Eval! http://www.perforce.com/perforce/loadprog.html _______________________________________________ Spamassassin-talk mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/spamassassin-talk
