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Conceptualizing Intervention Fidelity: Implications for Measurement, Design, and Analysis. Chris S. Hulleman, Ph.D. Implementation: What to Consider At Different Stages in the Research Process Panel presentation for the Institute for Education Sciences Annual Grantee Meeting September 7, 2011.
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Conceptualizing Intervention Fidelity: Implications for Measurement, Design, and Analysis Chris S. Hulleman, Ph.D. Implementation: What to Consider At Different Stages in the Research Process Panel presentation for the Institute for Education Sciences Annual Grantee Meeting September 7, 2011
Implementation vs. Implementation Fidelity Fidelity: How faithful was the implemented intervention (tTx) to the intended intervention (TTx)? Infidelity: TTx – tTx Implementation Assessment Continuum Descriptive What happened as the intervention was implemented? A priori model How much, and with what quality, were the core intervention components implemented? Most assessments include both
Linking Fidelity to Causal Models Rubin’s Causal Model: True causal effect of X is (YiTx – YiC) RCT is best approximation Tx – C = average causal effect Fidelity Assessment Examines the difference between implementedcausal components in the Tx and C This difference is the achieved relative strength (ARS) of the intervention Theoretical relative strength = TTx – TC Achieved relative strength = tTx – tC Index of fidelity
Implementation assessment typically captures… (1) Essentialor corecomponents (activities, processes, structures) (2) Necessary, but not unique,activities, processes and structures (supporting the essential components of Tx) (3) Best practices (4) Ordinary featuresof the setting (shared with the control group) Intervention Fidelity assessment
Why is this Important? Construct Validity • Which is the cause? (TTx - TC) or (tTx – tC) • Degradation due to poor implementation, contamination, or similarity between Tx and C External Validity • Generalization is about tTx – tC • Implications for future specification of Tx • Program failure vs. Implementation failure Statistical Conclusion Validity • Variability in implementation increases error, and reduces effect size and power
Why is this important? Reading First implementation results Effect Size Impact of Reading First on Reading Outcomes = .05 Adapted from Gamse et al. (2008) and Moss et al. (2008)
5-Step Process(Cordray, 2007) • Specify the intervention model • Develop fidelity indices • Determine reliability and validity • Combine indices • Link fidelity to outcomes Conceptual Measurement Analytical
Some Challenges • Analyses • Weighting of components • Psychometric properties? • Functional form? • Analytic frameworks • Descriptive vs. Causal (e.g., ITT) vs. Explanatory (e.g., LATE) • See Howard’s Talk Next! • Intervention Models • Unclear interventions • Scripted vs. Unscripted • Intervention Components vs. Best Practices • Measurement • Novel constructs: Standardize methods and reporting (i.e., ARS) but not measures (Tx-specific) • Measure in both Tx & C • Aggregation (or not) within and across levels • Future Implementation • Zone of Tolerable Adaptation • Systematically test impact of fidelity to core components • Tx Strength (e.g., ARS): How big is big enough?
Treatment Strength (ARS): How Big is Big Enough? *Averaged over 1st, 2nd, and 3rd grades (Gamse et al., 2008).
Thank You! And Special Thanks to My Collaborators: David S. Cordray Michael Nelson Evan Sommer Anne Garrison Charles Munter • Catherine Darrow, Ph. D. • Amy Cassata-Widera, Ph.D.
Chris Hulleman is an assistant professor at James Madison University with joint appointments in Graduate Psychology and the Center for Assessment and Research Studies. Chris also co-directs the Motivation Research Institute at James Madison. He received his PhD in social/personality psychology from the University of Wisconsin-Madison in 2007, and then spent two years as an Institute for Education Sciences Research Fellow in Vanderbilt University’s Peabody College of Education. In 2009, he won the Pintrich Outstanding Dissertation Award from Division 15 (Educational Psychology) of the American Psychological Association. He teaches courses in graduate statistics and research methods, and serves as the assessment liaison for the Division of Student Affairs. His motivation research focuses on motivation in academic, sport, work, and family settings. His methodological interests include developing guidelines for translating laboratory research into the field, and developing indices of intervention fidelity. As a Research Affiliate for the National Center on Performance Incentives, Chris is involved in several randomized field experiments of teacher pay-for-performance programs in K-12 settings. His scholarship has been published in journals such as Science, Psychological Bulletin, Journal of Research on Educational Effectiveness, Journal of Educational Psychology, and Phi Delta Kappan. Department of Graduate Psychology James Madison University hullemcs@jmu.edu
Treatment Strength Outcome .45 .40 .35 .30 .25 .20 .15 .10 .05 .00 TTx 100 90 85 80 75 70 65 60 55 50 Infidelity t tx Achieved Relative Strength (ttx) = 0.15 (85)-(70) = 15 tC “Infidelity” TC Expected Relative Strength = TTx - TC = (0.40-0.15) = 0.25