ERIC Number: ED426068
Record Type: Non-Journal
Publication Date: 1998-May
Reference Count: N/A
The Use of Piecewise Growth Models in Evaluations of Interventions.
Seltzer, Michael; Svartberg, Martin
In studies of interventions (e.g., remedial reading interventions), interest often centers on student academic progress or on changes in various attitudinal and affective measures, both during and after the intervention period. By enabling us to subdivide a time series into meaningful segments, and summarize important aspects of change in each segment, piecewise growth models provide a means of addressing key questions in intervention studies. In this report, the use of piecewise models is discussed for: (1) examining whether rates of progress for individuals in an intervention study, on average, slow down, remain constant, or speed up during the follow-up period; (2) assessing whether there is substantially more variability among individuals in their rates of change in the intervention period or in the follow-up period; and (3) identifying conditions under which rapid rates of progress are seen during the intervention period and sustained progress during the follow-up period. An appendix contains a coding scheme for the piecewise model. (Contains one figure, five tables, and six references.) (Author/SLD)
Publication Type: Reports - Evaluative
Education Level: N/A
Sponsor: Office of Educational Research and Improvement (ED), Washington, DC.
Authoring Institution: California Univ., Los Angeles. Center for the Study of Evaluation.; Center for Research on Evaluation, Standards, and Student Testing, Los Angeles, CA.