Current concepts in validity and reliability for psychometric instruments: theory and application.
Validity and reliability relate to the interpretation of scores from psychometric instruments (eg, symptom scales, questionnaires, education tests, and observer ratings) used in clinical practice, research, education, and administration. Emerging paradigms replace prior distinctions of face, content, and criterion validity with the unitary concept "construct validity," the degree to which a score can be interpreted as representing the intended underlying construct. Evidence to support the validity argument is collected from 5 sources:


BACKGROUND
Do instrument items completely represent the construct?
The relationship between the intended construct and the thought processes of subjects or observers.
Acceptable reliability and factor structure.
Correlation with scores from another instrument assessing the same construct.


CONCLUSIONS
Do scores really make a difference? Evidence should be sought from a variety of sources to support a given interpretation. Reliable scores are necessary, but not sufficient, for valid interpretation. Increased attention to the systematic collection of validity evidence for scores from psychometric instruments will improve assessments in research, patient care, and education.
Cook
David A
DA
Division of General Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA. cook.david33@mayo.edu
Beckman
Thomas J
TJ
D006801:Humans; D011594:Psychometrics; D015203:Reproducibility of Results