Wikipedia has become so popular and influential, that it was the subject of a formal evaluation by Nature magazine in 2005 (and a related dispute by Britannica afterwards).
This month, BBC Focus magazine has done a similar comparision with Encarta, Britannica, Infoplease and Wikipedia. While the study is not currently online, Wikipedian Arwel Parry posted a good summary of the findings on the Wikipedia mailing list.
The bottom line:
The Verdict:
Ratings: Infoplease 2/5; Encarta 3/5; Britannica 3/5; Wikipedia 4/5.
“All the encyclopaedias contained at least some errors and omissions, reinforcing the point that they should be viewed as starting points for your research rather than as all-encompassing fountains of knowledge. Infoplease fared poorest in our test with very little to get your teeth into. Encarta has a bright design and engaging multimedia options, but was let down by a dismal performance in the ‘current news’ test. Meanwhile Britannica’s long history was showcased in authoritative pages that are easy to get around. Our winner is Wikipedia which had the most detailed articles and was best equipped to deal with the ever-changing news about bird flu. While it was only marginally more accurate, it has close to 10 times more articles than the next biggest, all freely available. That means it’s most likely to have what you need.”
While this is far from definitive, and it only studied three topics – George Stephenson, Bird flu ( probably H5N1), Planetesimal – it is increasingly clear Wikipedia has areas of strength that compare well to the “big guys,” and cannot be so easily dismissed.