ABSTRACT

This study examined the effect of similar vs. dissimilar proficiency distributions on uniform DIF detection on a statewide eighth grade mathematics assessment. Results from the similar- and dissimilar-ability reference groups with an SWD focal group were compared for four models: logistic regression, hierarchical generalized linear model (HGLM), the Wald-1 IRT-based test, and the Mantel-Haenszel procedure. A DIF-free-then-DIF strategy was used. The rate of DIF detection was examined among all accommodated scores and common accommodation subcategories. No items were detected for DIF using the similar ability distribution reference group, regardless of method. With the dissimilar ability reference group, logistic regression and Mantel–Haenszel flagged 8–17%, and the Wald-1 and HGLM test flagged 23–38% of items for DIF. Forming focal groups by accommodation type did not alter the pattern of DIF detection. Creating a reference group to be similar in ability to the focal group may control the rate of erroneous DIF detection for SWD.

摘要

这项研究在全州范围的八年级数学评估中研究了相似和不相似的熟练度分布对统一DIF检测的影响。比较了具有SWD焦点小组的具有相似和不同能力的参考组的结果，对四种模型进行了比较：逻辑回归，分层广义线性模型（HGLM），基于Wald-1 IRT的测试和Mantel-Haenszel程序。使用了无DIF然后DIF的策略。在所有适应性评分和普通适应性亚分类中检查了DIF检测率。无论采用哪种方法，使用相似的能力分布参考组都未检测到DIF的项目。对于能力相异的参考组，逻辑回归和Mantel–Haenszel标记为8–17％，Wald-1和HGLM测试标记为DIF的项目为23–38％。通过适应类型形成焦点小组并没有改变DIF检测的模式。创建与焦点小组的能力相似的参考小组可以控制SWD的错误DIF检测速率。