Chapter 2: Packing and Unpacking Sources of Validity Evidence: History Repeats Itself Again

Validity has taken on many different meanings over the years, and different “types” or “aspects” of validity have been proposed to help define and guide test validation. In this chapter, I trace some of the history of test validity theory and validation and describe validity nomenclature that has evolved over the years. The historical review focuses on the Standards for Educational and Psychological Testing and its predecessors. Although the concept of validity has been described in various ways, there has long been consensus that validity is not an inherent characteristic of a test and what we seek to validate are inferences derived from test scores. The argument-based approach to validity as articulated in the current Standards provides sound advice for documenting validity evidence and for evaluating the use of a test for a particular purpose. Suggestions for further research and practice in test validation are provided.