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A Didactic Explanation of Item Bias, Item Impact, and Item Validity From a Multidimensional Perspective
Author(s) -
Ackerman Terry A.
Publication year - 1992
Publication title -
journal of educational measurement
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.917
H-Index - 47
eISSN - 1745-3984
pISSN - 0022-0655
DOI - 10.1111/j.1745-3984.1992.tb00368.x
Subject(s) - item response theory , perspective (graphical) , psychology , differential item functioning , item analysis , measure (data warehouse) , test (biology) , psychometrics , test validity , response bias , cognitive psychology , statistics , social psychology , computer science , artificial intelligence , developmental psychology , data mining , mathematics , paleontology , biology
Many researchers have suggested that the main cause of item bias is the misspecification of the latent ability space, where items that measure multiple abilities are scored as though they are measuring a single ability. If two different groups of examinees have different underlying multidimensional ability distributions and the test items are capable of discriminating among levels of abilities on these multiple dimensions, then any unidimensional scoring scheme has the potential to produce item bias. It is the purpose of this article to provide the testing practitioner with insight about the difference between item bias and item impact and how they relate to item validity. These concepts will be explained from a multidimensional item response theory (MIRT) perspective. Two detection procedures, the Mantel‐Haenszel (as modified by Holland and Thayer, 1988) and Shealy and Stout's Simultaneous Item Bias (SIB; 1991) strategies, will be used to illustrate how practitioners can detect item bias.