ABSTRACT
This chapter provides a practical framework for understanding psychometrics as they apply to neuropsychology. Initially, traditional psychometric concepts are reviewed, including reliability, validity, test referencing, and test theories. Second, the specific psychometric challenges that neuropsychologists face are placed in perspective. Third, validity is re-examined through a discussion of operating and sampling distribution characteristics of tests. The chapter discusses the applications of classical test theory are discussed. Psychometrically, these disciplines differ only in the level of complexity of procedures and patients. The complexities inherent in neuropsychological assessment require greater, not less, understanding of psychometric theory and application. A number of specific issues and principles were emphasized. An understanding of the reliability and validity of tests is essential to appreciating the limits to inferences that can be made from test performances. In neuropsychology traditional concepts of normal curve performance distributions must be questioned, because at times highly skewed distributions are found.
