"Handbook I is likely to be useful for undergraduate or graduate students who have an interest in pursuing quantitative research in educational and psychological testing, especially with datasets that contain multiple discrete outcomes. Master- and doctoral-level students seeking dissertation topics and doing literature reviews will find Handbook I a valuable resource."~Edward H. Ip, Wake Forest School of Medicine, Journal of the American Statistical Association"Based on scores in a battery of questions in Psychometrics, IRT is a paradigm for designing, analyzing, and interpreting the individual's abilities. Volume one describes models that are used in IRT. Basic knowledge of calculus and statistical theory are necessary to understand the contents of volume one. The references are thorough and up-to-date…I enjoyed reading this book. I recommend this book to psychologists, sociologists, statistics and computing professionals."~Journal of Statistical Computation and Simulation