default parameters - new vs old vs mine

[David Relson]

On 30 Mar 2004 09:04:32 -0500
Tom Anderson wrote:

> On Mon, 2004-03-29 at 20:19, David Relson wrote:
> > Parameters:
> >            robs     robx    min_dev  spam_co  ham_co
> > old      0.010000 0.415000 0.100000 0.950000 0.100000
> > new-0.99 0.017800 0.520000 0.375000 0.990000 0.450000
> > new-0.90 0.017800 0.520000 0.375000 0.900000 0.450000
> > new-0.70 0.017800 0.520000 0.375000 0.700000 0.450000
> > mine     0.017800 0.549138 0.435000 0.501000 0.376000
> >  
> > Classification Accuracy:
> > ver          hh     hu     hs     sh     su     ss
> > old       88673    650      7      0    604  74313
> > new-0.99  88965    362      3      2    850  74065
> > new-0.90  88965    362      3      2    549  74366
> > new-0.70  88965    357      7      2    427  74588
> > mine      88955    359     16      4    274  74639
> > 
> 
> Indeed, the false positives seem to be reduced from the "old" and
> "mine" values.  It's hard to believe that 4 hams scored over 0.7
> though, and 3 over 0.99.  I haven't had one yet score over 0.15, even
> those of the commercial variety (buy.com, cnet, bankrate, etc.).  Are
> you sure you classified them correctly?  I'd love to see what such a
> spammy ham looks like.

For those of you who are curious the attached .tgz file contains the 3
"hs" messages.  The three messages _are_ ham and also get high scores. 
Below are the message ids and the scores.

5599 0.994920 
6115 0.996870 
6120 0.991023

Note that 3 scored above 0.99 and 4 scored between 0.70 and 0.90.

>  The ham unsures are way too high for my taste.  My "hu" rate is less
> than 0.03% (where I've assumed 1 hu out of my total unsures because I
> can't divide zero meaningfully) to your 30-60% of total unsures.  My
> numbers skew way in favor of false negatives, where yours are fairly
> balanced.  I couldn't possibly accept a false positive rate higher
> than a false negative rate, even on the order of 0.01% vs 0.0025%. 
> I'd much rather reverse that ratio.  On the other hand, I receive 1-2
> fn's per day, and 8-10 su's, but IMHO that's more than worth zero fp's
> and hu's.

Remember that the above scores are "after the fact", i.e. messages have
been entered in the wordlists and are now being scored.  The scores the
messages get today are different from the scores they got when they
arrived because the wordlist is different.

> Just off-hand, I would suggest decreasing robx and increasing robs to
> better bias it.  But that's just based on my experience.

You're free to say that, however I've seen bogotune results that
contradict that idea.

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