Samuel Messick
Samuel Messick (1931–1998) was an American psychometrician and long-time Distinguished Research Scientist at Educational Testing Service (ETS) in Princeton. His 1989 chapter "Validity" in Educational Measurement (third edition) reorganized the modern understanding of what test validity is, and its influence reaches well beyond language testing into education, psychology, and the social sciences.
Messick's argument — now standard — is that all validity is ultimately construct validity. The older typology of "content, criterion, and construct" validities was not wrong so much as misleading: content and criterion evidence are types of support for the central construct claim. He added a further, more controversial move: validity has a consequential face, concerned with the social consequences of test use, not just the psychometric qualities of the instrument.
Career
- PhD from Princeton University
- Long career at Educational Testing Service, eventually Distinguished Research Scientist and Vice President for Research
- Past president of the American Psychological Association's Division on Evaluation, Measurement and Statistics
- Died in 1998
Published Work
- Messick, S. (1989). "Validity." In R. L. Linn (Ed.), Educational Measurement (3rd ed.). Macmillan.
- Messick, S. (1995). "Validity of psychological assessment: Validation of inferences from persons' responses and performances as scientific inquiry into score meaning." American Psychologist, 50(9).
- Extensive research on cognitive styles, personality assessment, and psychometric theory
Influence
- Gave language testing its dominant modern framework of construct validity
- His work underpins Bachman's models and contemporary approaches to assessment justification
- Forced the profession to treat test consequences as part of the validity argument, not an ethical afterthought