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ERIC Number: EJ799458
Record Type: Journal
Publication Date: 2008-Apr
Pages: 27
Abstractor: As Provided
Reference Count: 38
ISSN: ISSN-0027-3171
Evaluating Group-Based Interventions when Control Participants Are Ungrouped
Bauer, Daniel J.; Sterba, Sonya K.; Hallfors, Denise Dion
Multivariate Behavioral Research, v43 n2 p210-236 Apr 2008
Individually randomized treatments are often administered within a group setting. As a consequence, outcomes for treated individuals may be correlated due to provider effects, common experiences within the group, and/or informal processes of socialization. In contrast, it is often reasonable to regard outcomes for control participants as independent, given that these individuals are not placed into groups. Although this kind of design is common in intervention research, the statistical models applied to evaluate the treatment effects are usually inconsistent with the resulting data structure, potentially leading to biased inferences. This article presents an alternative model that explicitly accounts for the fact that only treated participants are grouped. In addition to providing a useful test of the overall treatment effect, this approach also permits one to formally determine the extent to which treatment effects vary over treatment groups and whether there is evidence that individuals within treatment groups become similar to one another. This strategy is demonstrated with data from the Reconnecting Youth program for high school students at risk of school failure and behavioral disorders. (Contains 1 table and 8 footnotes.)
Lawrence Erlbaum. Available from: Taylor & Francis, Ltd. 325 Chestnut Street Suite 800, Philadelphia, PA 19106. Tel: 800-354-1420; Fax: 215-625-2940; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: High Schools
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A