memory research, the distinction between incidental and intentional learning, and the distinction between immediate and long-term memory, and his interpretation of forgetting. Early work McGeoch's publication titled "The Vertical Dimensions of Mind" emphasizes the importance of longitudinal data and operational definition. Prior to the publication of this article, most studies were cross-sectional in design. In this paper, McGeoch defends the importance of considering longitudinal data in research. He notes that learning is a pervasive construct which influences the understanding of all psychological phenomena. He is also one of the first researchers to describe different types of learning: incidental and intentional, and different types of memory: short- and long-term. Later work In his publication titled "Forgetting and the law of disuse," McGeoch criticizes Thorndike's theory of the Law of Disuse, which posits that information is forgotten over time if it is not activated. McGeoch argues that the passage of time has no bearing on forgetting; rather, forgetting can be better understood in terms of interference that takes place during the interval between initial learning and test. Following the introduction of the concept of Retroactive inhibition, McGeoch developed the transfer theory of retroactive inhibition. This theory identifies two major contributors to forgetting: retroactive inhibition and change in context between learning and recall, and influenced how forgetting is understood today. More specifically, McGeoch's work set the stage for the Two-factor Theory of Interference. McGeoch also wrote an introductory textbook on human learning, which was published posthumously. Summary McGeoch is recognized as a pioneer in the field of human learning and memory. He changed the way researchers understand human forgetting by disproving Thorndike's law of disuse, encouraging Longitudinal study, and distinguishing incidental learning from intentional learning. He also identified retroactive inhibition as a mechanism for forgetting. Notable publications: McGeoch, J. A., & Irion, A. L. (1952). The psychology of human learning. References Kimble, G. A., & Schlesinger, K. (1985). Topics in the History of Psychology (Vol. 1). Psychology Press: New York, NY. https://books.google.com/books/about/Topics_in_the_history_of_psychology.html?id=ZTV9AAAAMAAJ McGeoch, J.A. (1919) The present status of psychology. Ed. by J. V. Breitwieser. Thesis (M.A.)--Colorado college https://archive.org/details/presentstatusofp1943mcge Pratt, C. C. (1943). John A. McGeoch: 1897-1942. The American Journal of Psychology, 56(1). 134-136. https://www.jstor.org/stable/1417911?seq=1#page_scan_tab_contents McGeoch, J. A., & Irion, A. L. (1952). The psychology of human learning. http://psycnet.apa.org/psycinfo/1952-05377-000 People from Argyle, New York 1897 births 1942 deaths 20th-century American psychologists University of Chicago alumni University of Washington faculty University of Arkansas faculty