Classroom-level influences on literacy skills in kindergarten through Grade 2, and on literacy and numeracy skills in Grades 3, 5, 7, and 9, were examined by comparing the similarity of twins who shared or did not share classrooms with each other. We analyzed two samples using structural equation modeling adapted for twin data. The first, Study 1, was of Australia-wide tests of literacy and numeracy, with 1,098; 1,080; 790, and 812 complete twin pairs contributing data for Grades 3, 5, 7, and 9, respectively. The second, Study 2, was of literacy tests from 753 twin pairs from kindergarten through Grade 2, which included a sample of United States and Australian students and was a reanalysis and extension of Byrne et al. (2010). Classroom effects were mostly nonsignificant; they accounted for only 2–3% of variance in achievement when averaged over tests and grades. Although the averaged effects may represent a lower-bound figure for classroom effects, and the design cannot detect classroom influences limited to individual students, the results are at odds with claims in public discourse of substantial classroom-level influences, which are mostly portrayed as teacher effects. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

中文翻译：

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估计课堂水平对识字和算术的影响：一项双胞胎研究。

通过比较共享或不共享教室的双胞胎的相似性，研究了课堂水平对幼儿园到 2 年级的识字技能以及对 3、5、7 和 9 年级的识字和计算技能的影响。我们使用适用于孪生数据的结构方程模型分析了两个样本。第一项是研究 1，是澳大利亚范围内的识字和算术测试，有 1,098 项；1,080；790 和 812 对完整的双胞胎分别提供了 3、5、7 和 9 年级的数据。第二项研究 2 是对从幼儿园到 2 年级的 753 对双胞胎的识字测试，其中包括美国和澳大利亚学生的样本，是对 Byrne 等人的重新分析和扩展。(2010)。课堂效应大多不显着；当对测试和成绩进行平均时，他们只占成就差异的 2-3%。尽管平均效果可能代表课堂效果的下限数字，并且设计无法检测仅限于个别学生的课堂影响，但结果与公共话语中关于课堂水平实质性影响的主张不一致，后者主要被描绘为教师效果。（PsycInfo 数据库记录 (c) 2020 APA，保留所有权利）