A combination of psychometric theory, history, philosophy and practice, with recent advances in analytical methods, metrology, and design. Psychometrics, Test Theory, and the Latent Factors Models began as a strong manuscript by Petr Blahu. Before his death he entrusted it to three co-authors who completed the book with in-chapter explanations. accessible mathematical appendices and computational guides. It was also expanded to include important advances since 2010 in psychometric methods, metrology, and the science of domain-specific design. Comprehensive in scope, the text contains computatational guides for the use of Stata, M-plus, and SPSS in Classical Test Theory, Item-Response Theory, and Factor Analysis. The authors highlight the practicality of software integration in order to successfully produce psychometrically sound research. Written by an international and decades-spanning team of experienced psychometricians, the text sets the goal of a future psychometrics that could earn its place in international metrology. The book is filled with suggestions, tips, and practical guidance about best practices and efficient strategies for modeling and model selection. In addition, the book includes important cautions and warnings about misuse and misinterpretations of common, but limited, analytical techniques. The book is historically informed, philosophically grounded, mathematically justified, and methodologically current. This important text: Applies intuitive reasoning and common examples to aid in the understanding of advanced technical concepts. Includes the conceptual, statistical, and philosophical background of psychometrics. Features recent advances advances and opposing views in psychometric theory. Contains concrete examples from current research, including cognitive tests and MRI data. Opens he vista for a future of testing with greatly increased use of well-constructed, learner-centered performance scales using computer-adaptive testing with feedback over multiple attempts. Psychometrics, Test Theory, and the Latent Factors Model is intended for forward-looking students and teachers in the behavioral, educational, health, and social sciences.