Differential item functioning (DIF) analysis is a statistical technique used for ensuring the equity and fairness of educational assessments. This study formulates a new DIF analysis method using the information similarity index (ISI). ISI compares item information functions when data fits the Rasch model. Through simulations and an international…

Test-item writing efforts typically results in item pools with an undesirable correlational structure between the content attributes of the items and their statistical information. If such pools are used in computerized adaptive testing (CAT), the algorithm may be forced to select items with less than optimal information, that violate the content…

While the seventh and ninth grade Maryland Functional Mathematics Tests (MFMT) appear valid and well constructed, the 65 percent passing rate for Montgomery County Public Schools' ninth grade students raises questions about the 81 percent passing score set for the MFMT. This standard is far stiffer than the 59 percent set for the Maryland…

The agreement between Mantel-Haenszel and Rasch procedures for identifying differential item functioning (DIF) on teacher certification tests was studied. Two specific research questions were addressed: (1) whether the Mantel-Haenszel and Rasch procedures identify the same items as functioning differently; and (2) how consistently each method…

In 1991, a study was conducted to determine the differential effects of placement testing on cultural, linguistic, and ethnic groupings in the San Diego Community College District (SDCCD). The study was conducted in two parts. The first part examined the characteristics of the students used to norm the Comparative Guidance Program (CGP) tests used…