Robert DeVellis demystifies measurement by relating it to familiar experiences and by emphasizing a conceptual rather than a strictly mathematical understanding. Students' attention is drawn to important concepts that are foundational for subsequent topics, with opportunities provided to test understanding through chapter summaries and exercises. The Fourth Edition includes more attention to content validity and its relationship to scale breadth; a more thorough examination of coefficient alpha's limitations and remedies; discussion of big measurement vs small measurement ; and additional discussion of the bifactor model in the chapter on factor analysis.
Prior to retiring in 2012, Robert F. DeVellis was Professor in the Department of Health Behavior, (Gillings School of Global Public Health) at the University of North Carolina at Chapel Hill. Dr. DeVellis has more than 35 years of experience in the measurement of psychological and social variables. He has been an active member of the Patient-Reported Outcomes Measurement Information System (PROMIS) consortium, a multisite National Institutes of Health (NIH) Roadmap initiative directed at identifying, modifying, testing, and disseminating outcome measures for use by NIH investigators. His role in PROMIS was as network-wide domain chair for Social Outcomes. He has served on the Board of Directors for the American Psychological Association's Division of Health Psychology (38), on the Arthritis Foundation's Clinical/Outcomes/Therapeutics Research Study Section, and on the Advisory Board of the Veterans Affairs Measurement Excellence Initiative. He is the recipient of the 2005 Distinguished Scholar Award from the Association of Rheumatology Health Professionals and is an associate editor of Arthritis Care and Research. In addition, he has served as guest editor, guest associate editor, or reviewer for more than two dozen other journals. He has served as principal investigator or co-investigator since the early 1980s on a series of research projects funded by the federal government and private foundations. He remains intellectually active in his editorial role and as a consultant on a variety of projects.