Clarence Lewis Barnhart (1900–1993) was an American lexicographer best known for editing the Thorndike-Barnhart series of graded dictionaries, published by Scott Foresman & Co. which were based on word lists and concepts of definition developed by psychological theorist Edward Thorndike.
Scott, Foresman paid for portions of his education in exchange for a promise of employment when his studies were complete.
The Scott Foresman editors brought Barnhart in to explain Thorndike's proposal after which the project was approved.
During World War II the United States Army approached the Linguistic Society of America seeking assistance to write a dictionary of military terms.
[1] While in New York, Barnhart found out that Random House had plans to produce an “Americanized” version of the Oxford Concise Dictionary.
Barnhart approached Random House and convinced them to let him take complete control of the project, from concept to design to implementation.
[5] Upon the formation of Pearson Education in 1998 the company retired the work in favour of their own Longman dictionary range.
[7] Consistent with the encyclopedia's use by young people, Barnhart wrote definitions which were both simple and accurate, and most entries include sample sentences or phrases.
[citation needed] Over his career of 64 years he and his staff accumulated a file of over 7 million quotations exhibiting contemporary usage of English words.
In the late 20th century he and his son helped to pioneer the use of electronically retrievable evidence from computerized files of news publications.