ALTERNATIVE MATHEMATICAL APTITUDE ITEM TYPES: DIF ISSUES

Abstract

Alternative mathematical items administered as prototypes at the Spring 1989 Field Trials are evaluated for differential item functioning (DIF) and differential speededness. Results for Algebra Placement (AP) and Student Produced Response (SPR) items are presented and contrasted to results obtained on the two current SAT-Math items: Regular Math and Quantitative Comparison. Analyses on comparisons between female and comparable male examinees, and between Asian-American, Black, and Hispanic examinees in comparison to comparable White examinees indicate that both of these alternative items appear to have DIF. Additional DD? analyses comparing the use of an internal versus an external matching criteria for the SPR items show evidence of negative DIF with either criteria. Results using the MH D-DIF statistic are more extreme than DIF results using the STD P-DIF index. The metric used to calculate the DIF indices may be accountable for the differences observed. Differential speededness results indicate that the two Math prototypes have slightly higher levels of differential speededness than the SAT-M. The SPR items pose an interesting problem for DIF. The definition of an appropriate DIF matching criterion for constructed response item types needs more study. Metric differences between methods and their effect on difficult or easy items also needs further exploration. Until these methodological issues are resolved, results of DD? studies on constructed response items should be interpreted with caution.