Providing conceptual and practical foundations in scale construction and psychometrics for producers and consumers of social/personality research, this guide covers basic principles, practices, and processes in scale construction, scale evaluation, scale use, and interpretation of research results in the context of psychological measurement. It explains fundamental concepts and methods related to dimensionality, reliability, and validity. In addition, it provides relatively non-technical introductions to special topics and advanced psychometric perspectives such as Confirmatory Factor Analysis, Generalizability Theory, and Item Response Theory. The SAGE Library in Social and Personality Psychology Methods provides students and researchers with an understanding of the methods and techniques essential to conducting cutting-edge research. Each volume within the Library explains a specific topic and has been written by an active scholar (or scholars) with expertise in that particular methodological domain. Assuming no prior knowledge of the topic, the volumes are clear and accessible for all readers. In each volume, a topic is introduced, applications are discussed, and readers are led step by step through worked examples. In addition, advice about how to interpret and prepare results for publication are presented.