This volume provides an overview of research from the learning sciences into understanding, enhancing, and measuring “deep comprehension” from a psychological, educational, and psychometric perspective. It describes the characteristics of deep comprehension, what techniques may be used to improve it, and how deep levels of comprehension may be distinguished from shallow ones. It includes research on personal-level variables; how intelligent tutors promote comprehension; and the latest developments in psychometrics. The volume will be of interest to senior undergraduate and graduate students of cognitive psychology, learning, cognition and instruction, and educational technology.