As far as I can judge, the Wikipedia's coverage of the natural and exact sciences is pretty good. Its humanities articles are an unmitigated disaster, though: they are replete with nonsense, plagiarism, falsities, and propaganda. I know a bit about psychology, economics, philosophy, and the history of certain parts of the world. Articles dealing with these fields are utterly and sometimes dangerously unreliable.Correct (I will give some examples over the next week). Wikipedia articles about set theory, pure mathematics, physics and other exact sciences are pretty good, as far as I can judge. But almost any article about the softer sciences and the humanities, and particularly philosophy, is a disaster.
Vaknin also has insightful things to say about teenagers and encyclopedias. He disparages the citation requirements of Wikipedia, which the teenage editors are obsessive about. The problem is that without credentials and education, an editor cannot tell the difference between good and bad sources. And as I commented here, they rarely bother to check the sources. If you understand the citation rules, you can make up any piece of nonsense you like, using a citation that does not support it in any way, particularly if you use academic papers and books which are not online, or obscure or out of print publications.
Vaknin says that even when the claims are 'verifiable' (i.e. backed up by reliable sources), research is not about hoarding facts (which Wikipedia generally is about, look for any article at random and you will soon come across a list - usually a list of silly things). "Wikipedia articles read like laundry lists of information gleaned from secondary sources". True research "is about identifying and applying context and about possessing a synoptic view of ostensibly unrelated data." (My emphasis).
Reagle, by contrast, is clearly a fan. Vaknin dismisses him entirely as a 'computer scientist'. I have only read his article on neutrality, and I was not impressed. It consists mostly of cursory remarks about 'neutrality', including a part about the X Windows System (what is that?), and a brief paragraph about the neutrality of Switzerland. It did not go on to ask the question implied by the title: whether Wikipedia is neutral. To do this, you need to take a reasonable sample of Wikipedia articles and compare them against some acceptable definition of neutrality. The article by James Hannam discussed in an earlier post did just that. Hannam took a definition of neutrality, namely, a topic balance which agreed roughly with the balance given by scholarly opinion, and found Wikipedia wanting. The entry on Alhazen is 7,000 words long and bristles with 126 footnotes. Major figures of the medieval Christian world such as William of Ockham* receive only 2,500 words.
I saw none of this critical approach in Reagle's essay. However, perhaps I should read more of his work and perhaps I am being unfair. The dispute is discussed in the Wikipedia signpost here, by Vaknin here. Reagle also has a weblog, and here is a video of one of his presentations.
*The entry on Ockham is also grossly misleading and incorrect. More later, perhaps.