Hi, I can just provide my personal history here. I appear in the credits of several popular reference works as everything from contributor to assistant editor-in-chief (a horrible title, I might add, but then again, so was the book). I have worked on these books for Simon and Shuster, Facts on File, Macmillan (before it was gobbled up by Simon and Shuster), Reader's Digest, Henry Holt, and Continuum. In each book, the facts were checked as Brian describes. In fact, I remember one senior editor at Simon and Shuster boasting about how they would pay grad students a certain amount of money for every mistake they found. They were eager to find errors. I now have a manuscript of a book that I wrote for Marshall Cavendish sitting on my desk. Every sentence was numbered and checked. I have been asked to help source the material. I will be happy to provide the email exchange. Mind you, I am not suggesting that we go to these extremes. I do think it is important, however, that people understand the lengths that publishers of reference works go to in order to ensure the quality of their products. Of course, some publishers are more meticulous than others. And despite all the efforts, mistakes always managed to slip in anyway. I am not about to say that because they do it, so should we. On the other hand, I will state my personal belief that with 850,000 articles already in the English Wikipedia, we should pay even more attention to quality than usual. Danny In a message dated 12/4/2005 12:40:47 PM Eastern Standard Time, lars(a)aronsson.se writes: You are right now arguing that it is necessary to source every fact, and then you are doing sweeping generalizations like this?! I'm not trusting your insight into the editorial principles of Encyclopaedia Britannica or indeed any other (printed) encyclopedia and thus I'm asking you to provide some sources.