THE PSYCHOMETRIC CHARACTERISTICS OF THE SAT FOR NINE HANDICAPPED GROUPS

Abstract

ABSTRACTThis study examined the psychometric characteristics of the Scholastic Aptitude Test (SAT) administered under special conditions for nine handicapped groups. Information about test characteristics is central to judging the accuracy and fairness of scores from SAT special administrations.Four psychometric characteristics were studied: level of test performance, test reliability, speededness, and extent of unexpected differential item performance. Psychometric comparisons were made between a nonhandicapped sample and each of nine different handicapped classifications. These contrasts were carried out twice; that is, they were replicated across two forms of the same test. The use of two samples taking different forms served to increase confidence in the stability of results and their applicability to other forms of the SAT.Results of the study showed that visually impaired students and those with physical handicaps achieved mean scores generally comparable to students taking the SAT in national administrations. Learning disabled and hearing impaired students scored lower than their nondisabled peers. Differences between Verbal and Mathematical performance were also comparable to those for the nondisabled reference group in all but the hearing impaired‐regular type test and visually impaired‐braille test samples. Hearing impaired‐regular students scored higher on Mathematical than on Verbal relative to their nondisabled peers, while visually impaired‐braille students showed no consistent superiority for Mathematical over Verbal.Analysis of test reliability revealed no practical differences in measurement precision across groups. Data on test speededness showed no evidence of disadvantage for disabled students; the amount of extended time allotted through special administrations appears to allow roughly equivalent proportions of handicapped and nondisabled examinees to complete the test.Because of the large number of groups and test items involved, unexpected differential item performance was examined through a two‐stage procedure. The first stage centered on the performance of item clusters. Individual items composing clusters showing questionable performance were then examined. This two‐stage procedure revealed only a few instances of differential item performance localized to visually impaired students taking the braille test.It is concluded that, with the exception of performance level, the psychometric characteristics of the SAT are generally comparable for the handicapped and nondisabled groups studied. These results lend support to the contention that scores from special administrations are fair and accurate measures of the developed scholastic abilities of handicapped students. Further studies of these scores–in particular, their factor structure and predictive validity–should provide additional information about their meaning for handicapped students.