ERIC Number: EJ787686
Record Type: Journal
Publication Date: 2008-Mar
Reference Count: 0
Clarifying Problems and Offering Solutions for Correlated Error when Assessing the Validity of Selected-Subtest Short Forms
Girard, Todd A.; Christensen, Bruce K.
Psychological Assessment, v20 n1 p76-80 Mar 2008
The correlation between a short-form (SF) test and its full-scale (FS) counterpart is a mainstay in the evaluation of SF validity. However, in correcting for overlapping error variance in this measure, investigators have overattenuated the validity coefficient through an intuitive misapplication of P. Levy's (1967) formula. The authors of the present article clarify that such corrections should be based on subtest-level versus FS-level data. Additionally, the authors propose a simple, modified equation incorporating FS-level scores that provides liberal and conservative validity measures for comparison across estimation methods, and they demonstrate its use in both a normative (N = 2,450) and clinical psychiatric (N = 216) sample.
Descriptors: Error of Measurement, Computation, Psychiatric Services, Correlation, Psychometrics, Program Validation, Structural Equation Models, Test Format, Test Validity, Equated Scores, Psychological Studies, Clinical Psychology
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Publication Type: Journal Articles; Reports - Evaluative
Education Level: N/A
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