Education Commons^™

Improvements For Differential Functioning Of Items And Tests (Dfit): Investigating The Addition Of Reporting An Effect Size Measure And Power, Keith D. Wright

Educational Policy Studies Dissertations

Standardized testing has been part of the American educational system for decades. Controversy from the beginning has plagued standardized testing, is plaguing testing today, and will continue to be controversial. Given the current federal educational policies supporting increased standardized testing, psychometricians, educators and policy makers must seek ways to ensure that tests are not biased towards one group over another.

In measurement theory, if a test item behaves differently for two different groups of examinees, this test item is considered a differential functioning test item (DIF). Differential item functioning, often conceptualized in the context of item response theory (IRT) is …

A Monte Carlo Study Investigating Missing Data, Differential Item Functioning, And Effect Size, Phyllis Lorena Garrett

Educational Policy Studies Dissertations

ABSTRACT A MONTE CARLO STUDY INVESTIGATING MISSING DATA, DIFFERENTIAL ITEM FUNCTIONING, AND EFFECT SIZE by Phyllis Garrett The use of polytomous items in assessments has increased over the years, and as a result, the validity of these assessments has been a concern. Differential item functioning (DIF) and missing data are two factors that may adversely affect assessment validity. Both factors have been studied separately, but DIF and missing data are likely to occur simultaneously in real assessment situations. This study investigated the Type I error and power of several DIF detection methods and methods of handling missing data for polytomous …