This book combines an overview of validity theory, trends in validation practices and a review of standards and guidelines in several international jurisdictions with research synthesis of the validity evidence in different research areas. An overview of theory is both useful and timely, in view of the increased use of tests and measures for decision-making, ranking and policy purposes in large-scale testing, assessment and social indicators and quality of life research. Research synthesis is needed to help us assemble, critically appraise and integrate the overwhelming volume of research on validity in different contexts. Rather than examining whether any given measure is 'valid', the focus is on a critical appraisal of the kinds of validity evidence reported in the published research literature. The five sources of validity evidence discussed are: content-related, response processes, internal structure, associations with other variables and consequences. The 15 syntheses included here, represent a broad sampling of psychosocial, health, medical and educational research settings, giving us an extensive evidential basis to build upon earlier studies. The book concludes with a meta-synthesis of the 15 syntheses and a discussion of the current thinking of validation practices by leading experts in the field.

Bruno D. Zumbo (Ph.D.) is Professor of Measurement, Evaluation, & Research Methodology with additional appointments in the Department of Statistics and the Institute of Applied Mathematics at the University of British Columbia (UBC) in Vancouver, British Columbia, Canada. Prior to arriving at UBC in 2000, he held Professorships in the Departments of Psychology, Education, and Mathematics at the University of Ottawa and then the University of Northern British Columbia. Over the last 25 years his interdisciplinary program of research has emerged to have broad interdisciplinary impact and as such is well-recognized in a variety of disciplines including psychology, applied social science research (quality of life and well being), assessment, educational research, language testing, health and human development. His research on validity and validation is at the core of his program of research and has elements of working at the foundations of the discipline, including philosophy of science, scientific methodology as well as practical psychometric methods at the intersection of measurement, statistical science and mathematics. Professor Zumbo's research and teaching have been recognized with international awards. He was recipient of the 2005 Samuel J. Messick Memorial Lecture Award for his work in validity, 2010 Research Fellow Award by the International Society for Quality of Life Studies and 2011/2012 UBC Killam Teaching Prize. He was also selected as a Fellow of American Educational Research Association (AERA) in 2011.

Eric K. H. Chan (Ph.D.) received his doctorate from the University of Calgary in Mental Health and Counseling and completed his post-doctoral training in the Measurement, Evaluation and Research Methodology (MERM) Program at the University of British Columbia (UBC) under the supervision of Professor Zumbo. Eric specializes in psychometric methods, knowledge synthesis (systematic review and meta-analysis) and patient- (and client-) reported outcome measures (PROM) and patient- (and client) reported experience measures (PREM) and consulting. He currently holds a prestigious Fellowship with the Technology Evaluation in the Elderly Network (TVN), with a focus on establishing consensus-based best practice guidelines for the selection and utilization of PROMs and PREMs to inform heath care. Prior to his fellowships he held a research appointment at the Canadian Council on Learning, where he conducted and provided advice on a number of systematic review and meta-analytic projects for policy decision making.