This report is a study of the operation of psychological processes in children in school, and of the application of knowledge about psychological processes to pupil personnel work. Investigated are three kinds of processes: perceptual, intellectual, and affective. The first seven chapters of the report present theoretical models, literature surveys, and research studies relevant to the study of perceptual and intellectual processes. Chapters eight and nine deal with affect processes; more specifically, with school anxiety. Chapter 10 presents a model for integrating research on psychological processes with pupil personnel work. (AUTHOR)