Sterba Sonya K, Rights Jason D
a Vanderbilt University.
Multivariate Behav Res. 2016 Mar-Jun;51(2-3):296-313. doi: 10.1080/00273171.2016.1144502. Epub 2016 Apr 7.
Item parceling remains widely used under conditions that can lead to parcel-allocation variability in results. Hence, researchers may be interested in quantifying and accounting for parcel-allocation variability within sample. To do so in practice, three key issues need to be addressed. First, how can we combine sources of uncertainty arising from sampling variability and parcel-allocation variability when drawing inferences about parameters in structural equation models? Second, on what basis can we choose the number of repeated item-to-parcel allocations within sample? Third, how can we diagnose and report proportions of total variability per estimate arising due to parcel-allocation variability versus sampling variability? This article addresses these three methodological issues. Developments are illustrated using simulated and empirical examples, and software for implementing them is provided.
项目分组在可能导致结果中分组分配变异性的条件下仍被广泛使用。因此，研究人员可能有兴趣量化并考虑样本内分组分配的变异性。在实际操作中要做到这一点，需要解决三个关键问题。第一，在对结构方程模型中的参数进行推断时，我们如何将抽样变异性和分组分配变异性产生的不确定性来源结合起来？第二，我们可以基于什么选择样本内重复的项目到分组分配的次数？第三，我们如何诊断并报告每个估计值中由于分组分配变异性与抽样变异性导致的总变异性比例？本文解决了这三个方法学问题。通过模拟和实证示例来说明进展情况，并提供了用于实施这些方法的软件。
