Prepares Data for Test Equating
Test equating by common items.
testEquatingData(DataList, AnchoringItems = NULL)
DataList |
a list of |
AnchoringItems |
a |
The purpose of this function is to combine items from different forms. Two cases are considered. Alternate Form Equating (where common and unique items are analyzed simultaneously) and Across Sample Equating (where different sets of unique items are analyzed separately based on previously calibrated anchor items).
A matrix containing the common and unique items.
Dimitris Rizopoulos d.rizopoulos@erasmusmc.nl
Yu, C.-H. and Osborn Popp, S. (2005) Test equating by common items and common subjects: concepts and applications. Practical Assessment Research and Evaluation, 10(4), 1–19. URL http://pareonline.net/getvn.asp?v=10&n=4
Rizopoulos, D. (2006) ltm: An R package for latent variable modelling and item response theory analyses. Journal of Statistical Software, 17(5), 1–25. URL http://www.jstatsoft.org/v17/i05/
# Let two data-sets with common and unique items
dat1 <- as.data.frame(rmvlogis(20, cbind(c(-2, 1, 2, 1), 1)))
names(dat1) <- c("CIt2", "CIt3", "CIt4", "W")
dat2 <- as.data.frame(rmvlogis(10, cbind(c(-2, -1, 1, 2, 0.95), 1)))
names(dat2) <- c("CIt1", "CIt2", "CIt3", "CIt4", "K")
# combine in one data-set by
lisForms <- list(dat1, dat2)
testEquatingData(lisForms)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.