History of the Encyclopædia Britannica the criteria by which the articles were sorted were not obvious even to scholars, despite Dr. Adler's claims that the sorting followed naturally from the "Propædia's" outline of all knowledge. In 1985, the "Britannica" responded to reader requests by restoring the index as a two-volume set. The number of topics indexed by the "Britannica" has fluctuated from 500,000 (1985, the same as in 1954) to 400,000 (1989,1991) to 700,000 in the current 2007 print version. Presumably, this recent increase reflects the introduction of efficient electronic indexing, since the size of the encyclopedia has remained nearly constant at approximately 40 million
Encyclopedia number of serious errors and about 1/3 more minor factual inaccuracies, but Wikipedia's writing tended to be confusing and less readable. Encyclopædia Britannica refuted the study's conclusions, deeming the study fatally flawed. Many academics, historians, teachers, and journalists reject Wikipedia as a reliable source of information, and Wikipedia is itself not a reliable source according to its own standards because of its openly editable wiki model. Critics argue Wikipedia exhibits systemic bias. Wikipedia is by far the largest web-based encyclopedia, but it is not the only one in existence. There are several much smaller, usually more specialized, encyclopedias on various