Update: Sorry to put this at the top, but the comments below mean I'm not making myself plain. The following post is an excercise in statistics and not in XP whoring. It's a comment on an observation.

I've begun to notice something, I'm sure there's many who've noticed it in the past as they're way higher up the XP ladder than I am.

Most days when I log into PerlMonks I have gained a few XP. In the beginning I'd post and then giggle with glee that people appreciated my post and my XP would go up. However, now that I've been here a while and have posted many times I don't get the same thrill. Which is a pity because it's now going up automatically.

It seems that there's a point beyond which you do not need to post to get an increase in XP. People find your old nodes and give them a vote so once you have enough old posts (cwalitee posts) your XP will rise automatically.

So where is this level?

First I thought OK, my XP is at about 1100 so that must be about the 'balance' level after which your XP will just automatically increase. Then I realised that if I had 2000 posts to get the 1100 XP then my posts mustn't be quality posts and I can't really expect an easy increase.

So maybe its because I've written 85 posts (this is 86). Once you have 86 posts, people will find the old ones and XP will automatically increase.

Of couse this also is untrue. It has to be a combination of both.


$XP = 1100; $posts = 86; $delta = 1.5; # (My XP is going up at about 1.5 per day) $days = 1108; # days since joining Perl Monks $average_per_post = $XP / $posts; # 12.7
We must deduce that a straight 12.7 $average_per_post doesn't work because my average would have been over that immediately after one of my more popular posts.

Therefore, the number of posts is either still individually relevent, not just as a factor of $average_per_post or that time is also a deciding factor.

Not being a mathematical genius, I can't get the next step. All I can deduce is that there is a function of these figures that will result in my $delta figure. Any geniuses reading this?

"Get real! This is a discussion group, not a helpdesk. You post something, we discuss its implications. If the discussion happens to answer a question you've asked, that's incidental." -- in clpm

Replies are listed 'Best First'.
Re: Tipping the Balance
by beth (Scribe) on May 13, 2004 at 07:10 UTC
    Your model is too simple. Consider these facts:
    • a good post will get a lot of upvotes (so far so good)
    • a good post will be prominently placed (say it makes the front page) and so its peak vote-gathering time lasts longer than that of a mediocre post
    • a post's rate of accumulating votes changes over its lifetime: it gets some votes at the beginning as people notice it; a lot of votes in sort of a "peak" stage; and then the number of votes per day begins to die off in what must be an exponential function (the same kind of function that governs, for example, a hot potato cooling off after it's removed from the oven). The votes/day asymptotically approaches zero.
    • Posts are made at different times, so their curves overlap.
    Consider this graph:
    |      .
    |    . 	   .   	
    |   .  	      .	
    |  .  	       .      
    |    	         .    
    |      	       	   .      
    | .    	       	      .      
    |  		          .     
    |. 		       	       .                  
     Fig 1. Popularity curve of a single post
     |  		   .  .			     
     |      	         .     	 .     	       	     
    v|    (a)      .	       	    .
    o|      .    .  	              .	  
    t|    . 	   .   	     	       .   
    e|   .  	  .   .	       	(c)   	 .     
    s|  .  	 .     .       	  .    	    .  
     |    	         .      .    . 	        .      	
     |      	       	   .           .       	     .	
     | .    	.      	      .        	   .	           .
     |   		          .            .       	       .
     |.     .	     . 	       .           .           
       	     t   i   m   e   -->     	    
      Fig 2. Overlapping curves for a moderately popular post 
    (a), a very popular post (b), and a minorly popular post 
    OK, so the ascii art kinda lost something in translation. Hopefully this gives you some idea of the mathematics of what you're up against. Note also that we were talking about "rates" and "accumulation", which suggest derivatives and integrals, respectively (but mostly integrals). You seem to be considering only the range at the end of all these curves, where the votes/day is close to zero, and it may be possible to do a linear approximation here. However, unless you are truly lazy (which maybe you are!) you will probably continue to make new posts at some frequency which should also be considered, so you would have to have at least a rough model of these exponential curves.
      OK, so the ascii art kinda lost something in translation.

      Oh yeah, I see it. It's a sailboat.</Mallrats>

Re: Tipping the Balance
by kvale (Monsignor) on May 13, 2004 at 00:19 UTC
    I think the answer is that you should not worry about XP so much :-)

    Regarding your analysis, I think the fallacy is that it is hard to talk about average nodes. Some posts tutorial in character could get recognized as valuable again and again; some throwaway comments that were cute at the time disappear into the murk.

    I don't know any monk that says: OK, I have reached some number of XP; time to rest on my laurels. For most, the fun is in the process of puzzling out questions, helping others and showing off cool techniques. That fun doesn't stop at some predestined XP level.


      Sorry for the misunderstanding, my post wasn't about determining a level where one can rest on one's laurels or where the fun stops. In fact I've advocated in the past for old nodes not to be votable which will stop the phenomenon.

      My post was mainly an observation and a math puzzle. As I said, I'm no longer enthralled by gaining XP.


      "Get real! This is a discussion group, not a helpdesk. You post something, we discuss its implications. If the discussion happens to answer a question you've asked, that's incidental." -- in clpm
Re: Tipping the Balance
by idsfa (Vicar) on May 13, 2004 at 01:22 UTC

    You are missing the (probably exponential) decay factor on old posts, which must also include corrections for multi-sigma posts (Best/Worst Nodes live forever). $delta is really most strongly a function of your current "visible" nodes (things in Newest, Best and Worst) plus a hard to calculate function of citations in other Monks' "visible" nodes, based on those nodes' popularity.

    $delta = $delta * &swag(now());

    If anyone needs me I'll be in the Angry Dome.
Re: Tipping the Balance
by hossman (Prior) on May 13, 2004 at 04:29 UTC

    Uh, I'm not sure where you're getting your numbers from, ut if all you're doing is looking at your overall XP, then maybe you're not aware of one key thing regarind XP. As described in the Experience docs...

    There are four ways to earn XP on Perlmonks. They are as follows:

    • 25% chance of gaining 1 XP every time you vote on a node
    • +1/6 number of votes cast if all votes are cast on any given day (This bonus only exists until you reach level 5)
    • 25% chance of gaining 2 XP points once a day if you were logged in within the past 24 hours from when the vote fairy does the rounds.
    • When people vote on nodes that you have written. If enough people up-vote your nodes, you will gain XP. If enough people down-vote your nodes, you will lose XP. Having a node deleted is bad for your XP.

Re: Tipping the Balance
by coldmiser (Hermit) on May 13, 2004 at 20:23 UTC
    Who cares about the XP. You have come to this website for one of a dozen reasons:

  • To learn
  • To help others learn
  • friendship
  • reference
  • because it's just a cool site
  • The list goes on and on... My point is, I've written only a handful of posts and I have more XP then I ever thought I would have. I still consider my knowledge of Perl limited and I come here mainly for reference, when I find a post that helps me (new or old) I give it a ++ and also any responses that may have helped me to understand my knowledge of the subject in question.

    I think you are putting too much importance in the XP given on this site. If XP were taken away completely 99.9% of us would still come to the site for many of the reasons previously mentioned (the other .1% are usually looking for any reason to leave the site forever - who knows, this post might even do it)

    Just come by on a regular basis, check out the posts and learn from them. If you are knowlegable enough to help someone out while you are here, even better (let's face it, you don't REALLY understand a subject until you can explain it to someone else). Many of us have developed good friendships with other monks while we are here (the chatterbox is a good indication of this) but it's all about learning and teaching.

    XP given at this site do not show your skill of the subject. Many people on this site have fewer XP then I do, but they are far more knowlegable of Perl and have been doing it longer then I have.

    Just relax, have fun, teach, learn and the XP will come.

      Spot on++

      Examine what is said, not who speaks.
      "Efficiency is intelligent laziness." -David Dunham
      "Think for yourself!" - Abigail
Re: Tipping the Balance
by artist (Parson) on May 13, 2004 at 20:47 UTC
    Positive increase in numbers about oneself would help anyone to be constantly alive and kicking. You tried to find out the rate of acceleration. You actually want something to be thrilled about at perlmonks. When you initiate, you become happy and joyful to see the rise of XP. It is time to find out new thrill at perlmonks.

    It's like a game. When you play a game, you become slightly happier when you do better. The previous state of mind doesn't matter much. PM/game gives you opportunity to raise your socre regardless of your current level. You want to maintain that thrill. If provided more statistics which goes on increasing daily, you would be happy. How about possible number of nodes you read and commented on it?. How about the number of messages that you got so far. How about number of minutes that you spent at Perlmonks? List could be endless.

    May be it's time to look at some other numbers in the life.

Re: Tipping the Balance
by flyingmoose (Priest) on May 14, 2004 at 18:29 UTC
    The real question is... how many billion years will it take me to attain "level vroom" :) And then, can I turn people into newts?