Abstract Personality represents a broad domain of human functioning having to do with variations across individuals in one's characteristic style of interacting with and adapting to the social environment. Various measurement models that have been applied to the measurement of personality are reviewed, including relatively recent technology-based innovations. A brief history of personality assessment is provided, with special emphasis given to important turning points in psychologists’ beliefs about and attitudes toward personality assessment. Methods for evaluating the reliability, validity, and utility of personality measures are described. Key structural and developmental concepts in personality theory are briefly reviewed. Finally, some of the applied uses of personality assessment are discussed. Personality assessment remains an important tool for understanding human behavior.