Effects of student groups on teachers’ and students’ perceptions of teaching quality.

Traditionally, ratings of teaching quality have been used to assess why some teachers are more effective than others. Nowadays, the focus of teaching quality research is shifting; Teachers’ adaptation of instruction to students and interactions between teacher and student behaviors are used increasingly to explain effective teaching. Uncertainty remains about the extent to which teachers adapt their instruction to students. Additionally, it is unclear which assessment scales measure stable teacher traits and which measures are affected by students. To address these questions, we conducted a quasi-experiment involving 146 German and math teachers and 3,980 of their students from various educational tracks in Germany. Teachers either taught the same group of students for two consecutive years or different groups each year. A difference-in-differences approach was employed to determine whether teaching quality ratings were more consistent when teachers taught the same group than when they taught different groups at both timepoints. Results suggest that especially student ratings of teaching quality and teacher ratings of student disruptions are affected by different student groups. Teachers’ ratings of their own instructional behaviors, however, are less affected. We discuss the causal informativeness of our findings regarding teachers’ instructional behaviors and give recommendations on how to interpret associations between different assessments of teaching quality with student outcomes.