A report on learning psychology and its relationship to the study of school learning emphasizes the increasing interaction between theorists and educational practitioners, particularly in attempting to learn which variables influence the instructional process and to find an appropriate methodology to measure and evaluate learning. "Learning Processes" is the subject of part I of this report and includes subheadings (1) reinforcement and extinction, (2) generalization, (3) discrimination, (4) attention, and (5) punishment. Part II, "Categories of Behavior," includes (1) rote verbal learning, (2) psycholinguistics, (3) memory, (4) concept learning, (5) problem solving and thinking, and (6) perceptual-motor skill learning. An extensive bibliography is included. This document is a preprint of a chapter to appear in the Encyclopedia of Educational Research, Fourth Edition, New York Macmillan, 1969. (MS)