This chapter discusses current issues in research on the validity of student ratings of teaching quality. We first discuss the advantages and limitations of student ratings of teaching quality based on theoretical considerations regarding the teaching quality concept. Research reveals that the validity of student ratings differs depending on the aspect of teaching quality being rated (i.e., classroom management, cognitive activation, or student support). Extending this research, we propose that future studies on the validity of student ratings should take into account students’ cognitive processing while responding to survey items. We discuss three areas that seem promising for future research: the complexity and comprehensibility of survey items, the referent and addressee of items, and finally, the idiosyncratic nature of student ratings.