This text offers a comprehensive account of the whole of the field of psychometrics. It covers psychometric theory, the different kinds of psychological test, applied psychological testing, and the evaluation of the best published psychological tests. It provides a detailed coverage of the field and places an emphasis on the practical application of psychometric theory in psychology and education, as well as in vocational, occupational and clinical fields. For this second edition the "Handbook" has been extensively revised and updated to include the latest research and thinking in the field at the end of the 20th century. The text challenges the scientific rigour of conventional psychometrics and identifies new ways forward.