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
CD-ROM encyclopedia CD-ROM encyclopedia A CD-ROM encyclopedia is an encyclopedia delivered as reference software on a CD-ROM disc for use on a personal computer. This was the usual way computer users accessed encyclopedic knowledge from early 1990s until the late 1990s. Later DVD discs replaced CD-ROMs and from mid-2000s internet encyclopedias became dominant and replaced disc-based software encyclopedias. Some examples of CD-ROM encyclopedia are Encarta, Grolier Multimedia Encyclopedia, and Britannica. CD-ROM encyclopedias were usually a MacOS or Microsoft Windows (3.0, 3.1 or 95/98) application on a CD-ROM disc. The user would execute the encyclopedia's software program to see a menu that allowed