Item response theory has become an essential component in the toolkit of every researcher in the behavioral sciences. It provides a powerful means to study individual responses to a variety of stimuli, and the methodology has been extended and developed to cover many different models of interaction. This volume presents a wide-ranging handbook to item response theory - and its applications to educational and psychological testing. It will serve as both an introduction to the subject and also as a comprehensive reference volume for practitioners and researchers. It is organized into six major sections: the nominal categories model, models for response time or multiple attempts on items, models for multiple abilities or cognitive components, nonparametric models, models for nonmonotone items, and models with special assumptions. Each chapter in the book has been written by an expert of that particular topic, and the chapters have been carefully edited to ensure that a uniform style of notation and presentation is used throughout. As a result, all researchers whose work uses item response theory will find this an indispensable companion to their work and it will be the subject's reference volume for many years to come * Introduction to testing as an engineering activity * Testing fundamentals * Defects, hypotheses, and tests * Strategies and methods for test case design I * Strategies and methods for test case design II * Levels of testing * Test goals, policies, plans and documentation * The test organization * Controlling, monitoring, evaluating and the testing process * Reviews as a testing activity * A measurement program to support product and process quality * Evaluating software quality-a quantitative approach * Defect analysis and prevention * The testers' workbench * Process control and optimization * The testing maturity model and test process assessment