This textbook, Advising on research methods: A consultant’scompanion, has been written for those who give advice on researchmethods in the social and behavioral sciences, including medicine andepidemiology. It aims to assist researchers in the field toproduce better – more accurate, valid, and reliable – results.Herman J. Ader has been a statistical consultant for many years at VU University in Amsterdam first at the Psychology department, later at theVU Medical center. With Don Mellenberg...

Psychological and educational tests are important tools of the behavioral sciences. Development, analysis, and application of tests are studied within psychometrics. Since modern psychometrics was

founded, both theory and practice of psychometrics have developed prosperously: Tests are continuously developed, classical theories are extended and subsumed under modern theories, and new applications are designed. Unfortunately, test construction and test theory are developing rather separately. T...