Now in its second edition, this important book examines test validity in the behavioral, social, and educational sciences by exploring three fundamental problems: measurement, causation, and meaning.Psychometric and philosophical perspectives and unresolved issues receive attention, as the authors explore how measurement is conceived from both the classical and modern perspectives. Split into three accessible sections, the first contrasts theories of measurement as applied to the validity of behavioral science measures, and the second considers causal theories of measurement as well as alternative theories of causation.The final section explores the meaning and interpretation of test scores as they apply to test validity, offering a conceptual overview of the field and its current state.Each carefully revised chapter begins with an overview of key theories and literature, concludes with a list of suggested readings, and features boxes with real-life situations that connect theory to practice.Examples of specific issues include:How tests can assess an attribute without measuring it. The role of values in test validity. Interpreting responses to the same question in different languages. Researchers, practitioners, and policy makers interested in test validity or developing tests will appreciate the book's cutting-edge review of test validity.Focusing on both the underlying concepts, as well as practical challenges of test construction and use, it also serves as a supplement in graduate or advanced undergraduate courses on test validity, psychometrics, testing, or measurement taught in psychology, education, sociology, social work, political science, business, criminal justice, and other fields.The book does not assume a background in measurement.