“It may be the case that non-experts are more cynical about information outside of their field and the difference comes from a natural reaction to rate unfamiliar articles as being less credible.”
While Slashdotters are arguing about this slowly bringing the discussion to the point “do you like Wikipedia or not?”, we can see how popular this Wikipedia project has become, the number of languages the articles have been translated to. And it keeps on growing and improving its content and quality.
A bizzare thing is that according to some of the researches, the articles contributed to Wikipedia encyclopaedia by non-experts are more valuable in case of information mentioned in their articles.
Whether this is better or worse than traditional, expert-based encyclopedias depends on who you ask. Nature did a highly-publicized comparative study between Wikipedia and the Encyclopedia Britannica last year in which they found that the two were similar in terms of accuracy.
In my opinion, an intuitive way of filtering the information by the person gives more useful data for an article then expert’s view on it. A user can easier identify what kind of data is needed by other users.