Social and Behavioral Sciences Commons^™

The Confounding Effects Of Ability, Item Difficulty, And Content Balance Within Multiple Dimensions On The Estimation Of Unidimensional Thetas, Ki Lynn Matlock

Graduate Theses and Dissertations

When test forms that have equal total test difficulty and number of items vary in difficulty and length within sub-content areas, an examinee's estimated score may vary across equivalent forms, depending on how well his or her true ability in each sub-content area aligns with the difficulty of items and number of items within these areas. Estimating ability using unidimensional methods for multidimensional data has been studied for decades, focusing primarily on subgroups of the population based on the estimated ability for a single set of data (Ackerman, 1987a, 1989; Ansley & Forsyth, 1985; Kroopnick, 2010; Reckase, Ackerman, & Spray, …