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
Encyclopædia Britannica was "Encarta", now discontinued, a modern, multimedia encyclopaedia that incorporated three print encyclopaedias: "Funk & Wagnalls", "Collier's" and the "New Merit Scholar's Encyclopedia". "Encarta" was the top-selling multimedia encyclopaedia, based on total US retail sales from January 2000 to February 2006. Both occupied the same price range, with the "2007 Encyclopædia Britannica Ultimate" CD or DVD costing US$40–50 and the Microsoft Encarta Premium 2007 DVD costing US$45. The "Britannica" contains 100,000 articles and "Merriam-Webster's Dictionary and Thesaurus" (US only), and offers Primary and Secondary School editions. "Encarta" contained 66,000 articles, a user-friendly Visual Browser, interactive maps, math, language and homework