A lot of people immediately find counterintuitive the authority of Wikipedia. If there is no small group of experts, how could the articles be accurate? Well, as any researcher will tell you, you really need data to judge such a claim. Thankfully, Nature magazine has published a comparative study of the accuracy of science articles in Wikipedia.
The exercise revealed numerous errors in both encyclopaedias, but among 42 entries tested, the difference in accuracy was not particularly great: the average science entry in Wikipedia contained around four inaccuracies; Britannica, about three.
Too bad that Brittanica contains so many errors! Teaching criticial evaluation of information sources is the key.
Reference: Chronicle Wired Campus Blog