This short study examines Wikipedia’s credibility by asking 258 research staff with a response rate of 21 percent, to read an article and assess its credibility, the credibility of its author and the credibility of Wikipedia as a whole. Staff were either given an article in their own expert domain or a random article. No difference was found between the two group in terms of their perceived credibility of Wikipedia or of the articles’ authors, but a difference was found in the credibility of the articles — the experts found Wikipedia’s articles to be more credible than the non-experts. —Thomas Chesney —An Empirical Examination of Wikipedia’s Credibility (First Monday)

It would be risky to extrapolate too much based on one study, but it’s still a useful data point. I tell my students not to cite Wikipedia in research papers, but they are free to use it during the information-gathering process, and for reference in an in-class oral presentation or something similar.