Various approaches of assessing instructional quality have emerged in educational research. In this article, we present two studies that apply the thin slices procedure, investigating the reliability and validity of the ratings of three dimensions of instructional quality based solely on the first impressions of untrained social observers. Thirty undergraduate students rated 30-s clips from English lessons (Study 1) and Math lessons (Study 2) regarding three quality dimensions. The findings suggest high reliability in these ratings. Multilevel confirmatory analyses suggested construct validity in terms of differentiation between the three dimensions of instructional quality. Finally, we found some overlap between the thin slices ratings of classroom management and constructive support with ratings of trained raters based on observations of full lessons, as well as students’ ratings of these dimensions. We discuss these results with respect to the potential of first impressions of untrained observers to measure instructional quality.

在教育研究中已经出现了多种评估教学质量的方法。在本文中，我们提出了两项​​应用薄片程序的研究，仅基于未经培训的社会观察者的第一印象，就教学质量三个维度的等级的信度和效度进行了调查。30名本科生对三个质量维度的英语课（研究1）和数学课（研究2）进行了30 s的评分。这些发现表明这些等级具有很高的可靠性。多层次的验证性分析表明，在教学质量三个维度之间的差异方面，建构效度是有效的。最后，我们发现，在课堂管理和建设性支持的薄片评分与经过培训的评估者的评分（基于对整个课程的观察以及学生对这些维度的评分）之间存在一些重叠。我们讨论这些结果，涉及未经培训的观察者对测量教学质量的第一印象的潜力。