@conference {1237,
	title = {Precision of Warm{\textquoteright}s weighted likelihood estimation of ability for a polytomous model in CAT},
	booktitle = {Paper presented at the annual meeting of the American Educational Research Association},
	year = {1999},
	note = {$\#$WA99-02 {PDF file, 604 KB}},
	address = {Montreal},
	author = {Wang, S and Wang, T.}
}
