Study finds no impact of increasing class size on student outcomes

January 05, 2015

By Scott Jaschik

Conventional wisdom (backed by many research studies) holds that students benefit from smaller classes. They receive more personal attention from instructors, who can spend more time evaluating each assignment turned in and can spend more time with each student. Many rankings systems reward colleges for small class sizes. Many potential undergraduates judge colleges on the availability of small classes.

But a large national study presented this weekend at the annual meeting of the American Economic Association challenges that conventional wisdom. The study finds that increases in online class size have no impact on student grades, student persistence in the course or the likelihood of students enrolling in future courses. The study focuses on courses that are not the size of large lectures or massive open online courses, but courses that are typical of those offered at many colleges and universities (in person and online). And the authors -- a research team from Stanford University -- write that their findings could suggest ways for colleges to save money, by enlarging online sections and cutting the number of instructors employed.

The study was conducted in online sections of courses offered by DeVry University, one of the largest for-profit institutions in the United States. DeVry's approach to course registration -- unlike the system used by most nonprofit colleges -- has students select courses without knowing which instructors will teach which sections. This eliminates the danger for a statistical study if students select popular instructors, who may have more success than others regardless of class size. When DeVry sections reach their enrollment caps, the university simply creates another section. In this experiment, the Stanford researchers were able to track outcomes for more than 100,000 students in nearly 4,000 sections of 102 different courses (undergraduate and graduate).