‘A Model of School Learning’ was published in the Teachers College Record in 1963. The article (Carroll, 1963a) represented an attempt to give a unified perspective on the types of basic variables, and their interrelationships, that were proposed as affecting a student’s degree of achievement in school subjects like reading, mathematics, and others that involve the cumulative acquisition of skills and knowledges. It seems to have been one of my more influential writings, even though I classify it as a ‘think piece’ rather than a solid report of research. I count 168 citations of it listed in the volumes of the Social Sciences Citation Index over the years 1969–80, but many other references to it are to be found. Further, the article has been reprinted and translated a number of times. 1 It has been a matter of some curiosity and interest to me to work through the various citations and subsequent research to see how the ideas set forth in the original article have been used, interpreted, emphasized, supported, not supported, questioned, or criticized over the years since its first publication. In this chapter I take the opportunity to comment on these uses and reactions, and to discuss the climate of educational theory and practice over the past several decades that nurtured the continuing interest in the model of school learning (MSL).