Scholars of psychology Embretson (U. of Kansas) and Reise (U. of California-Los Angeles) explains the psychometric method that is increasingly being used for contemporary psychological tests. Their treatment would be especially useful to psychologists and social scientists familiar with small-scale cognitive and personality measures, or those who want to use the theory to analyze scales used in their own research. They use concepts that would be known to graduates and practitioners of psychology. Annotation c. Book News, Inc., Portland, OR (booknews.com) This book develops an intuitive understanding of IRT principles through the use of graphical displays and analogies to familiar psychological principles. It surveys contemporary IRT models, estimation methods, and computer programs. Polytomous IRT models are given central coverage since many psychological tests use rating scales. Ideal for clinical, industrial, counseling, educational, and behavioral medicine professionals and students familiar with classical testing principles, exposure to material covered in first-year graduate statistics courses is helpful. All symbols and equations are thoroughly explained verbally and graphically. Item Response Theory (IRT) is increasingly the psychometric method used for contemporary psychological tests. The goal of this book is to explain IRT. The book is especially useful to psychologists and other social scientists who are familiar with small scale cognitive and personality measures, or to those who want to use IRT to analyze scales used in their own research. It is also useful for graduate students and practitioners who want to understand the contemporary psychometric foundations of the tests that they administer. Familiar psychological concepts are used to help explain various IRT principles. The book develops an intuitive understanding of IRT principles through the use of graphical displays and analogies to psychological principles. The