This paper presents an update of a 2010-literature review on class size research completed as background in preparation of an affidavit on class size provided by the lead author in the case of "British Columbia Teachers' Federation v. British Columbia," argued before the Supreme Court of British Columbia in 2010, appealed ultimately to…

A decade ago, many education leaders dismissed student achievement data and systematic research as having only limited utility when it came to improving schools or school systems. That was the "old stupid." But now the pendulum has swung the other way. In the "new stupid," data-based decision making and research-based practice can stand in for…

Social science research suggests that reducing class size has its largest effects on the achievement of minority and inner-city children during the first year of formal schooling. Despite scholarly disagreements about the implications of specific studies on class size, economists generally agree that targeted class-size policies rest on stronger…