Validity and Validation

Abstract

This book is an introduction to validity theory and to the methods used to obtain evidence for the validity of research and assessment results. The book pulls together the best thinking from educational and psychological research and assessment over the past 50 years. It briefly describes validity theory's roots in the philosophy of science. It highlights the ways that these philosophical perspectives influence concepts of internal and external validity in research methodology, as well as concepts of validity and reliability in educational and psychological tests and measurements. Each chapter provides multiple examples to help the readers see how validation work is done in practice, from the ways we design research studies to the ways we interpret research results. Of particular importance is the practical focus on validation of scores from tests and other measures. The book also addresses strategies for investigating the validity of inferences we make about examinees using scores from assessments, as well as how to investigate score uses, the value implications of score interpretations, and the social consequences of score use. With this foundation, the book presents strategies for minimizing threats for validity as well as quantitative and qualitative methods for gathering evidence for the validity of scores.