A SAS macro for estimating and visualizing individual growth curves


Journal Article

Longitudinal data analyses can be usefully supplemented by the plotting of individual growth curves. Unfortunately, such graphics can be challenging and tedious to produce. This article presents and demonstrates a SAS macro designed to automate this task. The OLStraj macro graphically depicts ordinary least squares (OLS)-estimated individual trajectories, describes interindividual variability in OLS-estimated growth parameters, and identifies possible outlier observations. Analytical developments are briefly outlined, and the use of the macro is demonstrated, with particular attention paid to the potential utility of the macro as both a data screening and post hoc diagnostic device. Potential limitations of the macro and suggestions for future developments are discussed. It is hoped that the program will be of use to applied researchers who seek to maximize the effectiveness of growth curve models in answering questions about stability and change.

Full Text

Duke Authors

Cited Authors

  • Carrig, MM; Wirth, RJ; Curran, PJ

Published Date

  • January 1, 2004

Published In

Volume / Issue

  • 11 / 1

Start / End Page

  • 132 - 149

International Standard Serial Number (ISSN)

  • 1070-5511

Digital Object Identifier (DOI)

  • 10.1207/S15328007SEM1101_9

Citation Source

  • Scopus