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University of Nebraska - Lincoln

Social and Behavioral Sciences

College of Education and Human Sciences: Dissertations, Theses, and Student Research

IRT

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Full-Text Articles in Education

Investigating The Fit Of The Generalized Graded Unfolding Model (Ggum) When Calibrated To Irt Generated Data From Dominance And Ideal Point Models, Abdulla Alzarouni Jul 2021

Investigating The Fit Of The Generalized Graded Unfolding Model (Ggum) When Calibrated To Irt Generated Data From Dominance And Ideal Point Models, Abdulla Alzarouni

College of Education and Human Sciences: Dissertations, Theses, and Student Research

The assessment of model fit in latent trait modelling, better known as item response theory (IRT), is an integral part of model testing if one is to make valid inferences about the estimated parameters and their properties based on the selected IRT model. Though important, the assessment of model fit has been less utilized in IRT research than it should. For example, there have been less research investigating fit for polytomous dominance models such the Graded Response Model (GRM), and to a lesser extent ideal point models such as the Generalized Graded Unfolding Models (GGUM), both in its dichotomous and …


Improving Irt Parameter Estimates With Small Sample Sizes: Evaluating The Efficacy Of A New Data Augmentation Technique, Brett P. Foley Jul 2010

Improving Irt Parameter Estimates With Small Sample Sizes: Evaluating The Efficacy Of A New Data Augmentation Technique, Brett P. Foley

College of Education and Human Sciences: Dissertations, Theses, and Student Research

The 3PL model is a flexible and widely used tool in assessment. However, it suffers from limitations due to its need for large sample sizes. This study introduces and evaluates the efficacy of a new sample size augmentation technique called Duplicate, Erase, and Replace (DupER) Augmentation through a simulation study. Data are augmented using several variations of DupER Augmentation (based on different imputation methodologies, deletion rates, and duplication rates), analyzed in BILOG-MG 3, and results are compared to those obtained from analyzing the raw data. Additional manipulated variables include test length and sample size. Estimates are compared using seven different …