A good understanding of the foundations of psychological assessment and measurement is central to both applied and theoretical psychology. Having many years experience as an applied psychologist, trainer and university lecturer, Keith Coaley outlines in an accessible way the key ingredients of psychological assessment, providing case studies to illustrate their application, making it an ideal textbook for courses on psychometrics or psychological assessment. Case studies demonstrate the variety of contexts in which assessment is conducted. With their help readers will be able to prepare for professional practice using the wide variety of test materials available in the modern world. The book covers the nature of assessment, basic components, how tests are made, underlying statistics, reliability and validity, assessment of intelligence, abilities and personality, non-psychometric approaches, as well as ethical and professional issues and modern developments. A final chapter explains how readers can construct their own tests.