16.2 not as effective

[David Relson]

On Sun, 25 Jan 2004 18:17:55 -0000 (GMT)
Andrew Norman wrote:

> > Has anyone noticed that bogofilter 16.2 is just not as effective
> > against
> 
> <snip>
> 
> > Any idea why this would be happening?  I am tempted to go and revert
> > to previous versions to figure out exactly where the change occured,
> > but I figured I'd ask first to see if anyone knew what was going on.
> 
> Have you considered the possibilty that it is not bf that has changed
> but the spam itself ?
> 
> I am still using bf build 0.13.6.2 and all of a sudden, 10 days or so
> ago, I started getting far more spam not filtered. I went from one or
> two spam messages incorrectly classified as ham a day to 20 or 30.
> Most of these spams appear to be being generated by the same bit of
> software (the resulting gibberish in the body and the format of the
> names it uses are fairly obvious).
> 
> Time for me to upgrade to the latest version of bf to see if that
> catches them.

Hello Andrew,

I'm definitely seeing an increase in quantity of spam.  Each of the last
3 months I've received more spam than ever before (5386 in Oct, 7062 in
Nov, and 9015 in Dec).  Bogofilter has already nailed 8112 this month,
so I'm on the path of another record breaker.

Switching from 0.13.6.2 to 0.15.13 (or, even better, 0.16.4 :-) you will
likely see a temporary hit in accuracy.  With bogofilter having changed
to case-sensitive tokens and tagging all header lines, there will be a
lot of tokens seen by the new bogofilter that are not in your wordlists.
 Training with a bunch of recent ham and spam will help you get past any
changeover effects.

David

P.S.  0.16.4 (current) is at least as good as 0.15.13 (stable).  There
have been changes to the supporting programs, but nothing of
significance to the bogofilter binary itself.  The newer version will
also more closely match the code in the next release series (0.17.x). 
I'd recommend using 0.16.4 :-)