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dc.contributor.authorAwuor, Risper Akeloen
dc.date.accessioned2014-03-14T20:14:06Zen
dc.date.available2014-03-14T20:14:06Zen
dc.date.issued2008-06-19en
dc.identifier.otheretd-07172008-130938en
dc.identifier.urihttp://hdl.handle.net/10919/28321en
dc.description.abstractThis simulation study focused on determining the effect of unequal sample sizes on statistical power of SIBTEST and Mantel-Haenszel procedures for detection of DIF of moderate and large magnitudes. Item parameters were estimated by, and generated with the 2PLM using WinGen2 (Han, 2006). MULTISIM was used to simulate ability estimates and to generate response data that were analyzed by SIBTEST. The SIBTEST procedure with regression correction was used to calculate the DIF statistics, namely the DIF effect size and the statistical significance of the bias. The older SIBTEST was used to calculate the DIF statistics for the M-H procedure. SAS provided the environment in which the ability parameters were simulated; response data generated and DIF analyses conducted. Test items were observed to determine if a priori manipulated items demonstrated DIF. The study results indicated that with unequal samples in any ratio, M-H had better Type I error rate control than SIBTEST. The results also indicated that not only the ratios, but also the sample size and the magnitude of DIF influenced the behavior of SIBTEST and M-H with regard to their error rate behavior. With small samples and moderate DIF magnitude, Type II errors were committed by both M-H and SIBTEST when the reference to focal group sample size ratio was 1:.10 due to low observed statistical power and inflated Type I error rates.en
dc.publisherVirginia Techen
dc.relation.haspartRAA_ETD.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectMonte Carlo simulationen
dc.subjectcombination ratiosen
dc.subjectsample sizeen
dc.subjectnominal p-valueen
dc.subjectDIF detectionen
dc.subjectDIF magnitudeen
dc.subjectstatistical poweren
dc.subjectdifferential item functioningen
dc.titleEffect of Unequal Sample Sizes on the Power of DIF Detection: An IRT-Based Monte Carlo Study with SIBTEST and Mantel-Haenszel Proceduresen
dc.typeDissertationen
dc.contributor.departmentEducational Leadership and Policy Studiesen
dc.description.degreePh. D.en
thesis.degree.namePh. D.en
thesis.degree.leveldoctoralen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineEducational Leadership and Policy Studiesen
dc.contributor.committeechairSkaggs, Gary E.en
dc.contributor.committeememberAlexander, M. Daviden
dc.contributor.committeememberDeater-Deckard, Kirbyen
dc.contributor.committeememberMiyazaki, Yasuoen
dc.contributor.committeememberWolfe, Edward W.en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07172008-130938/en
dc.date.sdate2008-07-17en
dc.date.rdate2009-08-04en
dc.date.adate2008-08-04en


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