Eighth-Grade Pupils in the Netherlands
Snijders and Bosker (1999) use as a running example a study of 2287 eighth-grade pupils (aged about 11) in 132 classes in 131 schools in the Netherlands. Only the variables used in our examples are supplied.
nlschools
This data frame contains 2287 rows and the following columns:
langlanguage test score.
IQverbal IQ.
classclass ID.
GSclass size: number of eighth-grade pupils recorded in the class (there
may be others: see COMB, and some may have been omitted
with missing values).
SESsocial-economic status of pupil's family.
COMBwere the pupils taught in a multi-grade class (0/1)? Classes which
contained pupils from grades 7 and 8 are coded 1, but only
eighth-graders were tested.
Snijders, T. A. B. and Bosker, R. J. (1999) Multilevel Analysis. An Introduction to Basic and Advanced Multilevel Modelling. London: Sage.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
nl1 <- within(nlschools, {
IQave <- tapply(IQ, class, mean)[as.character(class)]
IQ <- IQ - IQave
})
cen <- c("IQ", "IQave", "SES")
nl1[cen] <- scale(nl1[cen], center = TRUE, scale = FALSE)
nl.lme <- nlme::lme(lang ~ IQ*COMB + IQave + SES,
random = ~ IQ | class, data = nl1)
## IGNORE_RDIFF_BEGIN
summary(nl.lme)
## IGNORE_RDIFF_ENDPlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.