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Full-Text Articles in Education
Dissecting The Impact Of Dif/Dbf On Ability Estimation And Person Fit, Kevin Cappaert
Dissecting The Impact Of Dif/Dbf On Ability Estimation And Person Fit, Kevin Cappaert
Theses and Dissertations
Prior research has shown that differential item functioning (DIF) and differential bundle functioning (DBF) can influence ability estimation in unidimensional item repose theory (IRT); however, the relationship between ability estimation and uniform and non-uniform DIF/DBF has not been thoroughly investigated. Therefore, a simulation study was conducted to more thoroughly investigate how DIF/DBF and other related factors influence ability estimation in IRT. The factors examined included bundle size, the sum of uniform DIF in a bundle, magnitude of non-uniform DIF in each item in a bundle, balance of reference and focal group examinees, test length, and impact. Results indicated that an …
Dif Analyses In Multilevel Data: Identification And Effects On Ability Estimates, Yao Wen
Dif Analyses In Multilevel Data: Identification And Effects On Ability Estimates, Yao Wen
Theses and Dissertations
Fairness is an important issue in educational testing in that different groups of examinees should have equal probabilities of answering an item correctly, provided they have the same capabilities. Therefore, differential item functioning (DIF) analyses were developed due to the possibility of bias in cognitive or achievement tests. Data are multilevel structured in educational testing as students are nested within teachers who are nested within schools, and which may further be nested within districts. Although DIF analyses have been discussed for decades, they are rarely investigated in multilevel data. In this study, DIF analyses in multilevel data were investigated via …