This commentary highlights convergent themes from four articles in the March 2009 issue of "Educational Researcher" on measuring classroom instruction. Classroom instruction is a complex enterprise that occurs at the intersection of teachers, students, and texts within the surrounding classroom, school, and community environments. Progress in studying the complexity of classroom instruction on a large scale relies on our ability to pose research questions at the appropriate levels of analysis and to attempt to answer the questions using rigorous methods. These articles contribute to this task by sharing theoretical and practical viewpoints based on systematic programs of mixed methods research. The value of this body of research is reinforced through evidence of its impact on teaching practices and student learning.