An Evaluation of Multiple Single-Case Outcome Indicators Using Convergent Evidence Scaling

Abstract

The purpose of this article is to evaluate the consistency of five single-case outcome indicators, used to assess response-to-intervention data from a pilot Tier 2 reading intervention that was implemented at an elementary school. Using convergent evidence scaling, the indicators were converted onto a common interpretive scale for each case (N = 5). None of the quantitative effect size measures converged with summary visual inspection ratings. Lack of convergence was also observed between parametric and nonparametric effect size estimates. Within this study, indicator selection had a significant impact on individual treatment evaluations. Implications for professional practice and program evaluation are discussed.