ABSTRACT
This chapter explores several key requirements for research and professional discourse, including the necessity for clarity. It summarizes the extent and depth of the sustained inquiry into class size (CS) since 1900 by highlighting growth of the knowledge base. The chapter shows the consistency of the class-size research both for short-term and for long-term outcomes, from projects to evaluations to experiments, and explains how and why positive outcomes accrue in small classes. CS might seem straightforward and simple: The number of students in a class for whom the designated teacher is responsible and accountable is the CS definition used. As more knowledge about CS and its effects becomes available, debates about CS reemerge. With a history of inquiry, educators and policy makers should have learned much about CS. Teacher is responsible and accountable for the student's growth and development: Academics, Behavior, Citizenship, Development, Small focused learning groups.
