Toward an Understanding of Classroom Context: A Validation Study
Principal Investigators: Drew Gitomer, Ph.D., Educational Testing Services; Courtney Bell, Ph.D., Educational Testing Services
September 2008–June 2012
$813,910
The Classroom Assessment Scoring System (CLASS) is a promising observational instrument that measures student-teacher interactions in elementary school classrooms. Gitomer and Bell, along with colleagues from RAND (McCaffrey) and the University of Virginia (Pianta and Hamre), are testing the validity of the CLASS-S—an altered version of the CLASS meant for use in secondary school classrooms. They are also assessing different ways to implement the CLASS in an effort to optimize its efficiency. The investigators gathered data in 82 eighth and ninth grade algebra classrooms using three different strategies for completing the CLASS—the conventional observation by a classroom rater, video recordings of classrooms, and teacher self-assessment. For the validity analyses, the researchers collected measures of teacher and student characteristics, teachers’ math content knowledge, teachers’ and students’ views of intelligence, teachers’ beliefs about mathematics, and value-added measures based on student performance on the state standardized test and a pre-post test of algebra. In 2010, the investigators received a supplemental grant for additional data collection and scoring. Using factor analytic techniques, the empirical data support the theoretical model of CLASS-S. Sources of variance that have been identified include raters, mode (video versus live), lessons, experience in rating, and time of year. For instructional support and emotional support, scores decrease across the school year and also decrease along with raters’ experience and ongoing training. Overall, students are not learning much algebra. However, pre-test performance and gains are greater for eighth grade classes. The eighth grade classrooms also have higher CLASS-S scores, meaning that relatively stronger students do experience better teaching. However, whether this is the result of stronger teachers, rather than contextual factors that include the students, is unclear. In fact, while the relationship between CLASS-S scores and VAM is positive when other measures of prior achievement are not taken into account, positive correlations are not observed when adjustments for prior achievement are made. This raises important issues about the nature of the inference from CLASS scores to teacher quality. Overall, classroom organization dimension scores are high, most readily scored by observers, and most likely to be associated with teachers’ own evaluation of their practice. Emotional and instructional support dimension scores are much lower, more difficult to score, and less likely to be associated with teacher self-ratings.