Re: new feature for Red - adaptive scoring

[nc0273@experience.corp.netcom.com (Sean Lynch)]

I would use the following function:

(setq score (- score (* (sign score) (min score (max
          gnus-score-decay-constant (* (abs score)
            gnus-score-decay-scale))))))

Let's say gnus-score-decay-scale is set to 0.05 and
gnus-score-decay-constant is 3, this should cause the following:

Scores between -3 and 3 will be set to 0 when this function is called.

Scores with magnitudes between 3 and 60 will be shrunk by 3.

Scores with magnutudes greater than 60 will be shrunk by 5% of the
score.

This would make the score decay work very similarly to the way living
systems learn.  We could even make this an exponential function of the
time since the last time it was called on a given score.

We need to make sure, though, that this function is called a definite
number of times, so that we can define its behavior.

"This function sets all scores to 0 within five minutes of starting Gnus."

Perhaps it should be related to the number of articles that come
through that are affected by a given score.  This way, when a thread
dies, all scores related to it die more quickly.  

Just a thought.


>>>>> "Wes" == Wes Hardaker <hardaker@ece.ucdavis.edu> writes:

    Wes> larsi@ifi.uio.no (Lars Magne Ingebrigtsen) writes:

    Wes> |> I think a general "score decay" function might be more
    Wes> useful.

    Wes> Awesome.  This would also take care of those stupid threads
    Wes> that I got tired of reading because they turned into a
    Wes> different subject all together.

    Wes> I'm not sure you can do it with percentiles though.  Postive
    Wes> scores would never get to 0, which you'ld definately want.  I
    Wes> think a better thing to do would be to have it change by a
    Wes> set amount each time.  Positive scores should drop by say 3-5
    Wes> unless the current score was under that, then should drop to
    Wes> 0.  Negative scores would do the same.  That way old threads
    Wes> no longer existing would eventually end up at 0 in case some
    Wes> other dingo came along and started a new topic with the same
    Wes> subject.

    Wes> Wheeeee