10 The reliability and construct validity of student perceptions of teaching quality At the start of the 21st century, a new approach, founded in theories and def initions of teaching quality, entered the research f ield. Student perceptions of teaching quality were now investigated in order to identify the factors that influence the validity of these measures. For example, researchers argued that student perceptions of teaching quality may be associated with other variables (e.g., the popularity of the teacher, or the students’ average grades for a subject), and they studied students’ ability to distinguish between different aspects of teaching quality (Ferguson, 2012; van der Lans, 2017; the study presented in chapter 3 of this dissertation). Moreover, researchers increasingly studied the extent to which the student ratings of a teacher correlated with ratings by others, such as ratings by an external observer or a teacher’s self-evaluations (Clausen, 2020; Dobbelaer et al., submitted; van der Lans et al., 2015). Despite concerns about the validity and reliability of student perceptions of teaching quality, a signif icant number of studies have supported the use of student ratings as a valuable source of information about teaching quality and teacher performance (e.g., Atlay et al., 2019; Fauth et al., 2014; Kyriakides, 2005; van der Scheer et al., 2019; Wagner et al., 2013; Wallace et al., 2016). 1.3 VALIDITY OF STUDENT PERCEPTIONS OF TEACHING QUALITY The scientific debate on the merits of student perceptions of teaching quality has thus been going on for some time now. It has been argued that by measuring student perceptions, the quality of a teacher’s teaching can be assessed efficiently multiple times (equal to the number of students in a class; Kane & Staiger, 2012) at one and the same time, and the measurement can be repeated easily, because the teacher usually teaches the class at least once a week. Therefore, compared to classroom observations, for example, student perceptions can be reliable measures of teaching quality (Coles, 2002; Kane & Staiger, 2012). However, concerns regarding student teaching quality ratings generally involve arguments concerning their validity. That is: do they really measure what we want to measure? Although several types of validity can be distinguished, the construct validity and content validity of student perceptions are two of the main topics of this dissertation. Construct validity is about the underlying theoretical assumptions regarding (the items in) the measure. If the construct of “teaching quality” is intended to be measured by means of student perceptions, then the content of the items must represent and cover this construct adequately, based on the theoretical assumptions made by the developers of the measurement instrument. The
RkJQdWJsaXNoZXIy MjY0ODMw