The opposites dataframe consists of 144 observations within 36 individuals
that completed an inventory that assesses their performance on a timed cognitive task called
"opposites naming".
The dataset does not contain the empirical data within 35 individuals from the experiment by Willett (1988), but a simulation based on the multilevel model from Singer & Willett (2003) within 36 individuals.
oppositesthe following variables are available:
Subject: subject indicator
Time: a time variable, ranging 0-3
COG: cognitive skill, measured once (at time=0)
SCORE: score on opposites naming task
Willett, J.B. (1988). Questions and answers in the measurement of change. In: E. Rothkopf (Ed.), Review of research in education (1988-89) (pp. 345-422). Washington, DC: American Educational Research Association.
Singer, J.D., & Willett, J.B. (2003). Applied longitudinal data analysis. Modeling change and event occurence. NY: Oxford University Press, Inc.