This document discusses assessment and intervention in school psychology. It describes several assessment methods used in school psychology including introspection, observation, experimentation, differential methods, and clinical methods. Introspection involves self-examination of inner thoughts and feelings. Observation allows inference of mental processes by watching external behaviors. Experimentation employs controlled experiments to study relationships between variables. Differential methods measure individual differences using statistical techniques. Clinical methods involve diagnosing and treating individuals' adjustment problems. The document also outlines several interventions used in school psychology such as modifying environments, attitudes, and providing guidance, counseling, and various therapies.