THE PSYCHOMETRIC CHARACTERISTICS OF THE GRE GENERAL TEST FOR THREE HANDICAPPED GROUPS

Abstract

ABSTRACTThis study examined the psychometric characteristics of the Graduate Record Examinations (GRE) General Test for three handicapped groups. Information about test characteristics is central to judging the accuracy and fairness of General Test scores for handicapped students.Four psychometric characteristics were studied: level of test performance, test completion, test reliability, and unexpected differential item performance. Psychometric comparisons were made between nonhandicapped samples and each of three handicapped groups: visually impaired students taking large‐type, extended‐time administrations; visually impaired students taking timed, regular‐type administrations; and physically handicapped students taking timed, regular‐type administrations.Results of the study showed the performance of the visually handicapped groups to closely approximate that of nondisabled students. Physically handicapped students, however, performed substantially lower than the comparison group on two of the three General Test scales.Data on test completion showed evidence of possible disadvantage to the two groups of disabled examinees taking timed administrations. Evidence that handicapped students were somewhat less likely to complete the test was found for both groups on the Analytical sections and for one group on the first Quantitative section. Though these scores may, as a result, underestimate developed scholastic ability, any conclusion on this account must await the findings of further research.Test reliability was analyzed using both internal consistency and parallel‐forms methods. Neither method revealed any practical differences in measurement precision across groups.Because of the large number and general unreliability of individual item‐performance contrasts, unexpected differential item performance was examined through a two‐stage procedure. The first stage centered on the performance of item clusters. Items composing clusters showing questionable performance were then individually examined. This two‐stage procedure revealed only two instances–localized to visually impaired students taking the large‐type test–of differential item performance.In terms of both reliability and item behavior, the psychometric characteristics of the GRE General Test appear comparable for the handicapped and nondisabled groups studied. Though somewhat less comparable, test completion and performance levels also were similar across groups. Further studies of General Test scores–in particular, their factor structure and predictive validity–should provide additional information about their meaning for handicapped students.