@inbook {1954,
	title = {Developing item variants: An empirical study},
	year = {2009},
	note = {{PDF file, 194 KB}},
	address = {D. J. Weiss (Ed.), Proceedings of the 2009 GMAC Conference on Computerized Adaptive Testing.},
	abstract = {Large-scale standardized test have been widely used for educational and licensure testing.  In computerized adaptive testing (CAT), one of the practical concerns for maintaining large-scale assessments is to ensure adequate numbers of high-quality items that are required for item pool functioning.   Developing items at specific difficulty levels and for certain areas of test plans is a wellknown challenge.   The purpose of this study was to investigate strategies for varying items that can effectively generate items at targeted difficulty levels and specific test plan areas. Each variant item generation model was developed by decomposing selected source items possessing ideal measurement properties and targeting the desirable content domains. 341 variant items were generated from 72 source items.  Data were collected from six pretest periods.  Items were calibrated using the Rasch model.  Initial results indicate that variant items showed desirable measurement properties.  Additionally, compared to an average of approximately 60\% of the items passing pretest criteria, an average of 84\% of the variant items passed the pretest criteria.  },
	author = {Wendt, A. and Kao, S. and Gorham, J. and Woo, A.}
}
