3 ms·

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

3 points by srean 15y ago

Has there been any recent change to avg karma computation? 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.

chris_dcosta 15y ago
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!
- JoachimSchipper 15y ago
  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.)
  - chris_dcosta 15y ago
    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.
    - ImprovedSilence 15y ago
      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?
      - llambda 15y ago
        > ...although I suppose not knowing them prevents gaming the system. Something about security through obscurity...d'oh!
DanBC 15y ago
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.
- srean 15y ago
  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.
ig1 15y ago
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

3 points by srean 15y ago

chris_dcosta 15y ago

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!

JoachimSchipper 15y ago
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.)
- chris_dcosta 15y ago
  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.
  - ImprovedSilence 15y ago
    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?
    - llambda 15y ago
      > ...although I suppose not knowing them prevents gaming the system. Something about security through obscurity...d'oh!

DanBC 15y ago

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.

srean 15y ago
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.

ig1 15y ago

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