Introduction to Cognitive Diagnostic Models

This book is the world’s first comprehensive and unified textbook on cognitive diagnostic models (CDMs), integrating theory, application, and full software implementation within a single coherent framework. Unlike existing works that focus on isolated models, technical details, or fragmented case studies, this volume provides a standard, accessible, and self-contained introduction to the field. In that way, it substantially lowers the barrier to entry for newcomers while remaining rigorous enough for advanced readers. At the heart of the book is a unified perspective on CDMs as latent variable models designed to identify fine-grained mastery profiles of cognitive attributes underlying test performance. Moving beyond overall test scores and continuous proficiency scales emphasized in traditional item response theory, the book explains how CDMs rely on categorical latent structures that represent mastery and non-mastery of specific skills. These concepts are presented intuitively and conceptually, with minimal reliance on advanced mathematics, making the material approachable for educators, graduate students, and applied researchers. A distinctive feature of this volume is its strong emphasis on practical implementation. All methods and examples are fully implemented in the R language, allowing readers to immediately apply CDMs in real educational and research settings. Step-by-step illustrations guide users through model specification, estimation, interpretation, and diagnostic reporting. By combining interpretability, methodological coherence, and hands-on applicability, this single volume offers a comprehensive understanding of cognitive diagnostic models and their use in educational and psychological measurement.