This study utilizes an analysis of diminishing returns to examine the relationship between sample size and item parameter estimation precision when utilizing the Masters' Partial Credit Model for polytomous items. Item data from the standardization of the Batelle Developmental Inventory, 3rd Edition were used. Each item was scored with a…

This study aims to investigate the effect of methods to deal with missing data on item difficulty estimations under different test length conditions and sampling sizes. In this line, a data set including 10, 20 and 40 items with 100 and 5000 sampling size was prepared. Deletion process was applied at the rates of 5%, 10% and 20% under conditions…

The present report demonstrates the difference between classical test theory (CTT) and item response theory (IRT) approach using an actual test data for chemistry junior high school students. The CTT and IRT were compared across two samples and two forms of test on their item difficulty, internal consistency, and measurement errors. The specific…