Informative Versus Uninformative Ability Distributions With Characteristic Curve Linking Methods

• In Event: Linking, Equating, and Scaling: Issues and Practices

Abstract

Linking of two forms is an important task when using item response theory, particularly when two forms are administered to nonequivalent groups. When linking with characteristic curve methods, the ability distribution and weights associated with that distribution can be used with these methods. Commonly these are specified as equally spaced intervals from -4 to 4, but other options or distributional forms can be specified. The use of these different specifications of the ability distributions and their weights will be explored with a monte carlo simulation. Primary simulation conditions will include sample size, number of items, number of common items, ability distribution, and randomly varying population transformation constants. Implications for applied researchers will be discussed.

Authors

• Brandon LeBeau, The University of Iowa

• Keyu Chen, University of Iowa

• Wei Cheng Liu, University of Iowa

• Aaron McVay, University of Iowa