@inproceedings{EDM-2008-PavlikCWK,
	author        = "Philip I. Pavlik and Hao Cen and Lili Wu and Kenneth R. Koedinger",
	booktitle     = "{Educational Data Mining 2008, The First International Conference on Educational Data Mining, Montreal, Québec, Canada, June 20-21, 2008. Proceedings}",
	ee            = "http://www.educationaldatamining.org/EDM2008/uploads/proc/8_Pavlik_24.pdf",
	pages         = "77--86",
	publisher     = "{www.educationaldatamining.org}",
	title         = "{Using Item-type Performance Covariance to Improve the Skill Model of an Existing Tutor}",
	year          = 2008,
}