Wikipedia's user-generated content has made it the world's largest, and most derided, encyclopedia.

Part of the openness model has also led to 'edit wars' when the anonymous "editors" disagree with each other. The dynamics of these conflicts provide an interesting window into collaborative content production and the emergence and resolution of conflicts in an online environment, say researchers led by Taha Yasseri of the Budapest University of Technology and Economics.

Yasseri and co-authored identified Wikipedia pages that are either controversial, such as the articles for homosexuality and George W. Bush, or "peaceful," like pages for Benjamin Franklin and pumpkins. They found that the majority of pages are peaceful, but that edit wars were commonly waged between a small number of strongly disagreeing editors. 

Yasseri said, "Usually editors act in a rather independent, and uncorrelated manner, while during conflicts their activity becomes more intense and follows a more coherent pattern."

They found that consensus is generally reached in a reasonable time, even for controversial articles. There are a small number of articles where this is not the case, classified as never-ending wars, and these generally have many different active editors who have fought at different times.

Actually, there is an aspect their paper does not consider; that militants will continue to fight and normal people will not and that is why even controversial issues are resolved quickly.   A look at the Wikipedia entry for Science 2.0, for example, does not even mention the origins of Science 2.0, its oldest source is 2008, which means the creators of the article have an agenda that is not informational.  Various people from Science 2.0 have tried to suggest fixes at various times, to no avail so people give up.  A group of editors can simply bully newer people into submission and enforce a consensus even when there is none.   The overwhelming majority of people who edit on Wikipedia never return, which means conflicts are not being resolved, and people do not know just one thing - it means the exact opposite, namely the effect of "implicit regulations, and unwritten conventions" that Wikipedia claims does not exist.

Mark Moran at Finding Dulcinea has codified the problems into ten issues, but these are most relevant in science:

- You can’t rely on something when you don’t even know who wrote it.
The contributor with an agenda often prevails.
Individuals with agendas sometimes have significant editing authority.
...beginning in 2003, U.K. scientist William Connolley became a Web site administrator and subsequently wrote or rewrote more than 5,000 Wikipedia articles supporting the concept of climate change and global warming. More importantly, he used his authority to ban more than 2,000 contributors with opposing viewpoints from making further contributions.

According to The Financial Post, when Connolley was through editing, “The Medieval Warm Period disappeared, as did criticism of the global warming orthodoxy.”
 It has become harder for casual participants to contribute.
According to the Palo Alto Research Center, the contributions of casual and new contributors are being reversed at a much greater rate than several years ago. The result is that a steady group of high-level editors has more control over Wikipedia than ever.
Including people who have no idea what they are talking about.

Citation: Yasseri T, Sumi R, Rung A, Kornai A, Kertész J (2012) Dynamics of Conflicts in Wikipedia. PLoS ONE 7(6): e38869. doi:10.1371/journal.pone.0038869