Factual errors and outdated information were also reported, though extensive revisions to correct these took place in the mid-1980s, when the encyclopedia was converted to a two volume format.
Under chief editor Gorton Carruth the quality of the encyclopedia improved dramatically and by 1994 the set was "as accurate as could be expected of a work of more than two million words".
It also lacked biographical entries for people such as Maya Angelou, Toni Morrison, Philip Glass and Charles Drew.
[8] In terms of format, the 1994 version had 2,568 pages, 2.5 million words and 3,000 maps and illustrations, 95 per cent of which were in black and white.
Carruth was supported by a staff of 106 contributors, whose names, areas of responsibility, degrees and affiliation were listed at the beginning of each volume.
The set contained much practical advice, including how to write a resume, follow the stock market, save energy, conduct a self breast examination and "Do's and Don'ts of Pregnancy".
[11] There was also an optional supplementary third volume which contained information for taking standardized tests and a full color world atlas.