THE DIMENSIONALITY OF TESTS AND ITEMS
THE DIMENSIONALITY OF TESTS AND ITEMS
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DOI：
10.1111/j.2044-8317.1981.tb00621.x
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发表时间：
1981-01-01
影响因子：
2.6
通讯作者：
MCDONALD, RP
中科院分区：
文献类型：
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作者：
MCDONALD, RP
对测验和题目的维度概念进行了解释。一组n个测试或n个二元项目是一维的，当且仅当测试或项目拟合一个公因子模型，通常是非线性的，有一个公因子，即一个潜在特质。测验分数和项目反应一般都包含稳定的特定因素以及重测误差。双参数正拱形模型可以从通常为n + 1维的节理空间中获得。其中之一是潜在的特质连续体，而独特的（具体和错误）变化的维度。当且仅当项目符合完美尺度，则+1维塌陷为一维。将系数α视为衡量同质性、内部一致性或普遍性的系数的提议似乎没有充分的根据。
An explication is offered for the notion of dimensionality both for tests and items. A set ofntests or ofnbinary items is unidimensional if and only if the tests or the items fit a common factor model, generally non‐linear, with one common factor, that is, one latent trait. Both test scores and item responses in general contain stable specific factors as well as errors of retest measurement. The two‐parameter normal ogive model can be obtained from a joint space which in general is ofn+ 1 dimensions. One of these is the latent trait continuum while the remainingnare dimensions of unique (specific and error) variation. If and only if the items fit the perfect scale then+ 1 dimensions collapse into one dimension. Proposals to regard coefficient alpha as a coefficient measuring homogeneity, internal consistency, or generalizability, do not appear to be well founded.