Abstract Data from a large-scale math intervention program were used to evaluate the degree to which implementation fidelity (IF) and interventionist content knowledge were associated with student outcomes. Data were available for 33 interventionists serving 658 students in Grades 4–6 across one school year. A series of multilevel models were fit to the data to evaluate the impact of procedural IF and interventionists’ math content knowledge on students’ postintervention achievement, controlling for preintervention achievement and intervention dosage. Higher student posttest scores were observed for interventionists with an average fidelity rating of 95% or greater (β = .15); however, no effects on students’ math achievement scores were observed for interventionist content knowledge. Adding IF and a measure of interventionist content knowledge to the model explained a statistically significant amount of variance in growth estimates attributable to interventionists (15%). Results highlight the potential importance of ongoing evaluation and remediation of IF in the context of standardized supplemental intervention in math, while also providing some evidence that higher levels of content knowledge may not translate into greater impact in a standard-protocol intervention setting. Results suggest a need for more research examining characteristics of interventionists and aspects of implementation that may account for variance in student outcomes.

中文翻译：

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干预者实施保真度和内容知识作为数学干预有效性的预测指标的检验

摘要使用来自大型数学干预计划的数据来评估实施保真度（IF）和干预主义内容知识与学生成绩之间的关联程度。在一个学年中，有33位干预者的数据可供658至4-6年级的学生使用。一系列多层次模型适用于数据，以评估程序IF和干预者的数学内容知识对学生干预后成绩的影响，控制干预前成绩和干预剂量。干预者的学生测验分数更高，平均忠诚度为95％或更高（β= .15）；但是，对于干预者的内容知识，没有观察到对学生数学成绩得分的影响。在模型中添加IF和干预者内容知识的度量，可以解释统计学上可归因于干预者的增长估计值中的统计差异（15％）。结果强调了在数学上的标准化补充干预的情况下，对IF进行持续评估和修复的潜在重要性，同时还提供了一些证据，表明更高水平的内容知识可能不会对标准协议干预环境产生更大的影响。结果表明，需要进行更多研究，以检查干预者的特征和实施方面，这些方面可能解释学生成绩的差异。结果突出表明了在数学上的标准化补充干预的情况下对IF进行持续评估和补救的潜在重要性，同时还提供了一些证据表明，更高水平的内容知识可能不会对标准协议干预环境产生更大的影响。结果表明，需要进行更多研究，以检查干预者的特征和实施方面，这些方面可能解释学生成绩的差异。结果突出表明了在数学上的标准化补充干预的情况下对IF进行持续评估和补救的潜在重要性，同时还提供了一些证据表明，更高水平的内容知识可能不会对标准协议干预环境产生更大的影响。结果表明，需要进行更多研究，以检查干预者的特征和实施方面，这些方面可能解释学生成绩的差异。