new writeup re varying Robinson's s and the minimum deviation

[David Relson]

Greg,

Great results!  It's nice to see the flatness shown in the graphs.  With 
previous experiments using smaller corpora, the results have been highly 
sensitive s and md values.  A small change in either gives a big change in 
effectiveness.  As bogofilter's algorithm is generally quite effective in 
production use, the sensitivity to smalll changes has bothered me.

Given your finding that mindev around 0.35 and s around 0.1 is in the 
middle of the "good" range, I'm thinking of testing mindev = 
0.25,0.30,0.35,0.40,0.45 against s = 0.32, 0.1, 0.032, 0.001.

Given that I have fewer bogomips available for the test, it will be some 
hours before I have results.  It _will_ be interesting to see if your 
findings can be confirmed with other corpora.

Cheers!

David