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
History of the Encyclopædia Britannica focuses on material for children, which was much more profitable than its traditional encyclopedia. Used copies of the CD are available, but the online version of the Britannica as known up to 2012 is not available in 2018 from any vendor. In the 1980s Microsoft approached Britannica to collaborate on a CD-ROM encyclopedia, but the offer was declined. Senior managers at Britannica were confident in their control of the market and that their healthy profits would continue. At this time complete sets of the encyclopedia were priced between $1,500 and $2,200, and the product was considered part of a luxury