

Ask PG: Avg karma seems to be dropping even with #upvotes higher than avg - srean

Has there been any recent change to avg karma computation?<p>I noticed that my avg has been dropping consistently although my last few comments seem to have got more up-votes than my (pre-existing) average. Seems the site is telling me that I am doing something that I shouldnt be doing, but I am not sure what.
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chris_dcosta
This is a pure guess, but I think it's about right when I look at my own
dismal performance.

If your own avg Karma drops below 2 (because people downvote you for example)
you cannot upvote anything.

The problem with that is that if you only get 1 point per submission I sense
that it might just be mathematically impossible to get back above 2 again, and
worse, the more you participate the lower your average Karma gets.

As I say, just a guess based on my own score. I could be completely wrong. In
which case this post will probably be downvoted out of existence!

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JoachimSchipper
Are you _really_ sure? To the best of my knowledge, your karma _total_
determines the ability to downvote/flag.

(Note that the required karma total is periodically raised, perhaps the
threshold got raised above your current karma at some point in the past? ISTR
that it last got raised about a year ago.)

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chris_dcosta
What are you asking about? Am I sure about what?

I feel certain that pg posted a comment a while ago mentioning that he had re-
worked the algorithm and that an average below 2 meant your upvote did not get
counted. I can't find that thread though, but I expect others will explain it
better, although I would not expact the algorithm to be posted.

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ImprovedSilence
Hmm... It'd be interesting to know the "rules" to this karma thing, although I
suppose not knowing them prevents gaming the system. My karma is above 2, but
I haven't been able to downvote something for months. I guess I just downvoted
the wrong person/article?

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llambda
> ...although I suppose not knowing them prevents gaming the system.

Something about security through obscurity...d'oh!

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ig1
I believe the average is calculated over a moving time window, so possibly you
made some highly rated comments a while ago which have just fallen outside of
the window causing a drop in avg karma

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DanBC
There's some lag between people up-voting comments and the average karma being
calculated. Is that what you're seeing?

And, really, for a site like HN it's a shame that the word "average" is used
when mean, median, or modal would be nicer.

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srean
Well, if I look back a week then my average over that period would be 24.5 if
I throw out the comment that got most upvotes in that period. If I do the same
for the last month I would get 16.75. If I exclude last week from the last
month the avg turns out to be 9. All of these are higher than the avg that I
have.

Not too concerned with the average per se, but curious why I don't see tiny
upward bumps after (say weeks or months after) my comments get upvotes in
excess of my current avg.

So far my hypothesis is that since I do not comment very regularly (about 1
week in a month) they are falling out of the moving window. But still it does
not quite make complete sense.

