Notes
1. Although, to be fair, Britannica instituted a policy in 1933 to continuously revise every article for every printing, so these editions are themselves more fluid than we might think.
2. One example from a page on sport utility vehicles was edited on 11 March 2004, stating after a criticism of the low fuel mileage of SUVs: ‘The introduction of the 2005 Ford Escape, though, is predicted to hush a number of these critical voices …’ This page was later revealed to have originated from the Ford Motor Company in Dearborn, Michigan.
3. Encyclopedia Britannica took exception to this conclusion, taking issue with the methodology and conclusions of the study, which, incidentally, found about four errors per Wikipedia article and three per Britannica article. The surprising conclusion from the study may not be that Wikipedia is more accurate than expected, but that sources like Britannica, an expert‐authored source and held by most to be a gold standard of reliability, are themselves vulnerable and can harbour an unexpected number of incorrect facts. It should also be noted, however, that the study only looked at factual errors and not at more difficult problems such as how accurately the articles addressed the important issues in a particular field – something Britannica also pointed out.
4. With a few superficial exceptions. For example, a symbolic diagram may be correct or incorrect, or a doctored image may be said to be false.