The founding father of the Kirkpatrick Four Levels. From wikipedia: He is best known for creating a highly influential 'Four Level' model for training course evaluation, which served as the subject of his Ph.D. dissertation in 1954. Kirkpatrick's ideas were published to a broader audience in 1959 in a series of articles in the 'US Training and Development Journal', but they are better known from a book he published in 1994 entitled 'Evaluating Training Programs'. Other books that he has written on training evaluation include 'Transferring Learning to Behavior' and 'Implementing the Four Levels'.