C. A. Thomas, I. K. Davies, D. Openshaw, and J. B. Bird are instructors or directors at the British Royal Air Force School of Education. They are pioneers in the application of programmed learning in Britain and are highly regarded as forward looking and creative educational research workers. Their accomplishments include, in addition to this ingenious book, the design and development of the Empirical Tutor, one of Britain's major teaching machines, and the publication of a number of technical papers in the field of programmed learning.