This book describes the Reflective Judgment Model (RJM) and provides a comprehensive review of the research on it and the Reflective Judgment Interview (RJI). Chapter 1 defines reflective judgment as an often neglected aspect of critical thinking. Chapter 2 discusses stage-related assumptions that underlie RJM and relates RJM to current work in developmental psychology and to prior and current models of epistemological development. Chapter 3 describes RJM's seven stages. Chapter 4 focuses on the assessment of reasoning skills and contrasts the components necessary for assessing reasoning about ill-structured problems with those found in other common measures of thinking. Chapter 5 describes the assessment procedures used in measuring reflective judgment and summarizes alternative approaches to and new developments in the assessment of reflective judgment. Chapter 6 focuses on research on RJM. It describes a 10-year longitudinal study, summarizes findings from other longitudinal studies, and presents general patterns of development in reflective judgment based on the 1,700 individuals who have been assessed in cross-sectional studies using the RJI. Chapter 7 examines the relationship between RJM and other measures of intellectual development. Chapter 8 describes the relationship between the development of reflective judgment and the development of character. Chapter 9 focuses on the implications of RJM for college teaching and student development on the college campus. The text includes 12 tables, 4 figures, and 6 exhibits. Appendixes include materials on the RJI, 11 statistical tables, 296 references, and an index. (YLB)