Analysis and revision of the Depressive Experiences Questionnaire: examining scale performance as a function of scale length.
Revisions of the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976) have failed to replicate the degree of orthogonality routinely observed with the original Dependency and Self-Criticism scales. Item performance on the DEQ was examined by computing correlation coefficients between factor-derived scores and unit-weighted composite scores for Dependency and Self-Criticism as a function of (a) the importance of individual items in predicting factor-derived Dependency and Self-Criticism scores and (b) scale length. Analyses identified sets of unit-weighted items that optimally preserve the psychometric properties of the original DEQ scales, including between-scale orthogonality, while reducing the number of items used to measure Dependency and Self-Criticism. Findings were replicated in college (N = 172) and clinical (N = 83) samples. Limitations of exploratory principal components and confirmatory factor analysis as tools for revising scales are discussed.
Santor
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Department of Psychology, Dalhousie University, Halifax, Nova Scotia.
Zuroff
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DC
Fielding
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D000328:Adult; D003858:Dependency, Psychological; D003866:Depressive Disorder / Q000175:diagnosis*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D013997:Time Factors