SASmixed (version 1.0-4)

SIMS: Second International Mathematics Study data

Description

The SIMS data frame has 3691 rows and 3 columns.

Format

This data frame contains the following columns:

Pretot

a numeric vector giving the student's pre-test total score

Gain

a numeric vector giving gains from pre-test to the final test

Class

an ordered factor giving the student's class

Source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (section 7.2.2) Kreft, I. G. G., De Leeuw, J. and Var Der Leeden, R. (1994), ``Review of five multilevel analysis programs: BMDP-5V, GENMOD, HLM, ML3, and VARCL'', American Statistician, 48, 324--335.

Examples

str(SIMS)
if (require("lme4", quietly = TRUE, character = TRUE)) {
  options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
  ## compare to output 7.4, p. 262
  print(fm1SIMS <- lmer(Gain ~ Pretot + (Pretot | Class), data = SIMS))
  print(anova(fm1SIMS))
}