Wikipedia: emergent phenomenon?

Is Wikipedia a magical aggregator and filter of expertise from millions of different contributors? Or is it more like traditional encyclopedia projects, with a thousand or so core Wikipedians doing most of the work? The distribution of edits (a typical power law) supports the latter interpretation, but a detailed analysis of particular articles shows that important knowledge is injected by individuals who are not part of the core group.

Aaron Swartz: I first met Jimbo Wales, the face of Wikipedia, when he came to speak at Stanford. Wales told us about Wikipedia’s history, technology, and culture, but one thing he said stands out. “The idea that a lot of people have of Wikipedia,” he noted, “is that it’s some emergent phenomenon — the wisdom of mobs, swarm intelligence, that sort of thing — thousands and thousands of individual users each adding a little bit of content and out of this emerges a coherent body of work.”† But, he insisted, the truth was rather different: Wikipedia was actually written by “a community … a dedicated group of a few hundred volunteers” where “I know all of them and they all know each other”. Really, “it’s much like any traditional organization.”

The difference, of course, is crucial. Not just for the public, who wants to know how a grand thing like Wikipedia actually gets written, but also for Wales, who wants to know how to run the site. “For me this is really important, because I spend a lot of time listening to those four or five hundred and if … those people were just a bunch of people talking … maybe I can just safely ignore them when setting policy” and instead worry about “the million people writing a sentence each”.

So did the Gang of 500 actually write Wikipedia? Wales decided to run a simple study to find out: he counted who made the most edits to the site. “I expected to find something like an 80-20 rule: 80% of the work being done by 20% of the users, just because that seems to come up a lot. But it’s actually much, much tighter than that: it turns out over 50% of all the edits are done by just .7% of the users … 524 people. … And in fact the most active 2%, which is 1400 people, have done 73.4% of all the edits.” The remaining 25% of edits, he said, were from “people who [are] contributing … a minor change of a fact or a minor spelling fix … or something like that.” ...

[But what if we analyze the amount of text contributed by each person, not just the number of edits? See original for analysis of edit patterns of specific articles, including amount of text added.]

... When you put it all together, the story become clear: an outsider makes one edit to add a chunk of information, then insiders make several edits tweaking and reformatting it. In addition, insiders rack up thousands of edits doing things like changing the name of a category across the entire site — the kind of thing only insiders deeply care about. As a result, insiders account for the vast majority of the edits. But it’s the outsiders who provide nearly all of the content.

And when you think about it, this makes perfect sense. Writing an encyclopedia is hard. To do anywhere near a decent job, you have to know a great deal of information about an incredibly wide variety of subjects. Writing so much text is difficult, but doing all the background research seems impossible.

On the other hand, everyone has a bunch of obscure things that, for one reason or another, they’ve come to know well. So they share them, clicking the edit link and adding a paragraph or two to Wikipedia. At the same time, a small number of people have become particularly involved in Wikipedia itself, learning its policies and special syntax, and spending their time tweaking the contributions of everybody else.