Slashdot uses a unique community moderation system to determine which user comments are most valuable. The basic idea is that each comment starts with a certain "value," expressed in points ranging from -1 to +5. Anonymous posts start with a value of 0, and signed posts generally start with a value of 1. Users can then choose which comments they see by selecting from a "threshold" menu button at the top of the list of comments. That's when the fun begins!
Moderators, chosen from the pool of registered users based on their previous contributions to slashdot, are periodically given five "points" with which to moderate the comments of others. They can use the points to moderate a comment up or down. They can also choose from a set of descriptive words ("insightful," "interesting," "funny," "off-topic," "troll"). Users build "karma" by having their comments rated highly. "Karma" used to be an actual numerical value which was increased for positive moderations and decreased for negative moderations. However, it is now represented only as a qualitative value ("good," "positive," "negative," "excellent"), apparently an effort to reduce the number of users who view slashdot as a "game" you can "win" with more karma ["karma whores," in the slashdot vernacular].
Okay, now let's see how this system works in practice. I've chosen to analyze a portion of a discussion about a news story
describing a successful test of a military laser capable of destroying
artillery shells in flight. Here's a link to the archived conversation:
Laser Shoots Down Artillery Shell In Flight
The first poster starts off with a relatively interesting question:
wouldn't the momentum of the projectile still carry it forward to its
target? The first respondent, "kbonin," offers a fairly reasonable
response--the laser would cause the explosives within the projectile to
detonate, completely destroying it. The next response, by "Anonymous
coward" [respondents who post anonymously are automaticaly given this
shameful moniker], mentions that s/he has seen a television show
explaining that lasers destroy missiles by igniting the fuel that
propels them. The fact that this comment was posted just two minutes
after kbonin's response probably means that "Anonymous Coward" was
in the process of writing his/her own response when kbonin's
response was posted.
The conversation really starts to get interesting with ceejayoz's
response to Anonymous Coward. "*sigh* Insightful?" is a dig at the
moderation of Anonymous Coward's response. Then ceejayoz corrects the
factual error in Anonymous Coward's response--we're talking about
artillery here, not missiles.
MonadicIQ takes the conversation in another direction with a joke about
Captain Kirk. Apparently the moderators weren't as impressed with
MonadicIQ's original comment as they were with charlesbakerharris's
response: "That's a *phasor*. Lasers are so 2280." But in the end (not
the end of the conversation, just the end of the small portion I've
arbitrarily selected), the moderators are most impressed with TheSync's
observation that missiles kill with shrapnel, which the laser would
cause to fall short of the target.
What's interesting about slashdot is that the conversants are aware of
the varying levels of expertise of the individual participants, but
also that they have enough confidence in the slashdot system that they
believe the correct response will eventually be generated. The system works because the participants have implicitly agreed
to a set of conventions.
What complicates the scenario for online discussion is that the
"discussion" itself is not the same as a normal discussion--rather than
two participants, there are thousands, and there is no assurance that
anyone is "listening" to anything you "say." Indeed, in the snippet of
slashdot discussion I examine here, no one person speaks more than
once. What's most striking to me is that even though it's clear that
the online discussion is very different from a "real" one, the
participants instinctively act as though it is real, and they trust the moderation system to out those who flout the conventions of actual conversation.