ABSTRACT

Maintaining equivalent performance standards across forms is a psychometric challenge exacerbated by small samples. In this study, the accuracy of two equating methods (Rasch anchored calibration and nominal weights mean) and four anchor item selection methods were investigated in the context of very small samples (N = 10). Overall, nominal weights mean equating slightly outperformed Rasch equating for three of the four anchor item selection methods, but Rasch equating slightly outperformed nominal weights mean equating when anchor items were selected to be near the cut score. The results largely confirmed previous research on the utility of nominal weights mean equating for very small samples. In addition, the results provide useful guidance for small volume programs who wish to consider using Rasch for building and equating new forms. Lastly, the results underscored the importance of being mindful about the method for selecting anchor items when building new forms.

摘要

在各个表格之间保持等效的性能标准是心理上的挑战，小样本加剧了这一挑战。在这项研究中，在非常小的样本（N = 10）的情况下，研究了两种等效方法（Rasch锚定校准和平均权重平均值）和四种锚定项目选择方法的准确性。总体而言，公称权重等于略胜于Rasch，相当于四种锚定项目选择方法中的三种，但Rasch等于略强于标称权重，意味着等同于选择锚定项目接近切割得分时的情况。该结果很大程度上证实了先前对名义重量均值的研究，即等于非常小的样本。此外，结果为希望考虑使用Rasch构建和等同于新形式的小规模计划提供了有用的指导。最后，