This book presents a wide array of information on diverse but fundamental aspects of test theory and its application to practical problems in mental measurement for the advanced student and measurement professional. In general, these ideas can be classified under measurement science. From one of the best-known scholars in the field of tests and measurement, comes an authoritative, up-to-date, and comprehensive treatment of the oft-misunderstood and contentious field of making mental measurements, written for the advanced student and measurement professional. The author covers the good and the bad of each area within the field, carefully explaining the psychometrics, from classical and modern scale development, to validity evaluation, to traditional and current conceptions of reliability, to modern standard setting techniques, equating scales, and advances in test delivery and administration, as well as accomodating special circumstances. Throughout the text, there are many examples and relevant stories to hold the readers interest; and, it is organized in a way that makes it easy to locate specific topics. It is replete with up-to-date references, making it a wonderful resource for more detailed and scholarly study into many aspects of tests and measurement.