A Note on the Calculation and Interpretation of the Delta-p Statistic for Categorical Independent Variables
A Note on the Calculation and Interpretation of the Delta-p Statistic for Categorical Independent Variables
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DOI：
10.1007/s11162-009-9131-1
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发表时间：
2009-09-01
影响因子：
2.1
通讯作者：
Cruce, Ty M.
中科院分区：
文献类型：
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作者：
Cruce, Ty M.
本方法说明说明了常用的Delta-p统计量计算如何不适合分类自变量，并且本说明为逻辑回归的用户提供了修订的Delta-p统计量计算，该计算在研究两个或多个组之间预测结果概率的差异时更有意义。尽管人们不能完全证明当前Delta-p统计计算中的这种错误在多大程度上已经蔓延到整个领域，但随着越来越多的研究人员使用逻辑回归来研究分类结果，以及随着研究人员更密切地关注Delta-p统计作为一种向政策制定者和管理者传达逻辑回归模型结果的手段，错误的潜在影响是深远的。建议高等教育学者和机构研究人员在报告先前研究的Delta-p统计量时要谨慎，并在估计具有分类自变量的逻辑回归模型时采用本方法学说明中提出的Delta-p统计量的修正计算。
This methodological note illustrates how a commonly used calculation of the Delta-p statistic is inappropriate for categorical independent variables, and this note provides users of logistic regression with a revised calculation of the Delta-p statistic that is more meaningful when studying the differences in the predicted probability of an outcome between two or more groups. Although one cannot fully document the extent to which this error in the current calculation of the Delta-p statistic has spread across the field, the potential for error is far reaching as an increasing number of researchers use logistic regression to study categorical outcomes and as researchers look more closely at the Delta-p statistic as a means to communicate the results of logistic regression models to policy makers and administrators. It is recommended that higher education scholars and institutional researchers use caution when reporting the Delta-p statistic from prior studies and that they adopt the revised calculation of the Delta-p statistic presented in this methodological note when estimating logistic regression models with categorical independent variables.