Exchangeability of Brief and Abbreviated Intelligence Tests: Illuminating the Influence on Error Variance Components on IQs

This study examined the relations between and the exchangeability of IQs from four brief and abbreviated intelligence tests. All four tests were administered to 40 college students and scored by one set of examiners and later scored by a second examiner. All IQs were submitted to a Generalizability theory analysis to examine the relative contributions of error variance components of “test” and “examiner” and their interactions in producing variance in IQs relative to the object of measurement, individual differences in general intelligence. Despite very strong mean reliability coefficients (i.e., .91 to .96), the resulting dependability coefficient was .75, which indicated suspect dependability. The inadequate dependability coefficient from this study indicates that IQs are not as exchangeable as one might have assumed based on internal consistency reliability estimates, inter-rater reliability estimates, and convergent validity evidence