The impact of class size on teaching and learning has had a long and vigorous research history. Indeed this topic was probably the first pedagogical issue researched in American higher education with the first formal articles appearing in the early 1920s [9].
In the last twenty years or so, this extensive literature has developed a consensus on the impact of class size on the effectiveness of teaching and learning at the collegiate level. For many institutions, the increasing importance of generating FTEs has accentuated the belief that there is a substantial trade-off between class size and student learning. This newsletter will explore this consensus in three specific areas: the impact of class size on student academic performance, the impact of class size on student attitudes toward the class and subject matter, and the impact of class size on student evaluations of faculty.
Perhaps the most surprising (and well documented) result in the literature on class size in higher education is that class size seems to have little or no impact on the acquisition and even the retention of basic course material by students. For many faculty members, this research result seems counterintuitive. Most of us implicitly believe that students in smaller classes learn more and better than students in larger classes. Yet, a number of research studies at different times and places conclude that students in larger classes end up knowing just as much about the subject matter as students in smaller classes. Some of the traditional anecdotal evidence supporting the better academic performance in smaller classes derives from the fact that the better students often seek out the smaller classes. Better motivated students populate the smaller classes at many institutions. Removing this difference in populations explains much of the better performance by students in smaller classes [5].
More specifically, most recent studies on class size and academic achievement conclude that (1) class size has no effect on the recall and retention of facts and information during a course as measured by student performance on objective questions or examinations and (2) scores on standardized examinations two years after a course is over were virtually identical between students in large and small classes so that there was no discernible difference in the retention of academic information.
However, there is one significant difference between large and small classes that appears consistently in the research. When it comes to the attainment of higher-order academic skills such as problem solving, written expression, and critical thinking, students in smaller classes do acquire more of these skills than do students in larger classes. Thus, while the literature demonstrates that large classes prove no obstacle to the acquisition of specific, course-related, factual knowledge, students in larger classes are at some disadvantage in developing an ability to think better by using skills beyond the basic acquisition of information.
Here again the various research studies over the years have reached some consensus. Smaller classes do lead to a more positive attitude toward the subject matter of the course. In the most extensive study of class size and student attitudes [8], the specific conclusions were:
Faculty members fear that students in larger classes may systematically lower their faculty evaluations to express their dissatisfaction with the size of the class. Fortunately, the consensus in the literature on class size and student evaluations provides a good deal of comfort to faculty who teach the larger classes and have their students evaluate faculty teaching. Research consistently indicates that class size does not affect student evaluations of faculty in any significant manner. Students tend to minimize the impact of general course-related characteristics when evaluating faculty teaching effectiveness. Only a very small part of the overall evaluation of a faculty member is apparently contingent on environmental or physical factors such as time of day, classroom amenities, and class size perceived to be beyond the faculty member's control. The overwhelmingly important determinants in overall student evaluation of faculty are the instructor-specific characteristics such as enthusiasm, course organization, instructor's command of course material, fairness of grading practices, and so on. Essentially almost all studies found that class size was statistically insignificant in explaining instructor evaluations by students. One recent study [4] did find some evidence that class size can have some measurable impact on the middle range of student evaluations. Excellent and poor faculty are unaffected by class size. However, the larger class sizes do somewhat penalize those faculty members whom student rate in the "fair" to "good" range.
Before exploring some possible responses to these research results, some perspective is necessary. Most of the studies defined small classes as having fewer than 70 or so students in them. Thus, most of the classes taught at Mankato State would qualify as small classes in most of these studies. On the other hand, a very recent attempt to calculate the average class size of lower division classes at all institutions of higher education in the US found that the average class size for those classes was 28 students with only 10% of all those classes holding more than 44 students [2]. (This average is somewhat deceiving since the author did remove the extreme class sizes from his statistics. For example, lecture classes with less than 5 students or more than 150 were omitted from his statistics.) Perhaps class size is more a relative measure rather than some absolute numerical dimension. There is, for most professors, some threshold number of students beyond which the teaching and testing methods must change to accommodate the larger number of students. Several studies have hypothesized that this threshold ranges from between 10 to 20 students [6] [7]. Students also have their own working definition of small and large classes that may or may not coincide with the definition of the instructor. The research results might best apply if courses perceived by either the instructor or the students as "small" or "large" based on their own experience.
Ideally majors or potential majors should enroll in smaller sections of a given class while non-majors should enroll in the larger sections. The smaller class setting will help develop an appreciation for the subject matter and will help encourage the important higher order skills necessary for success in the major. Larger sections of the same course will not harm those students in their acquisition of the basic factual knowledge in the course.
Registration information available to students should include the maximum class size to facilitate student choice. Some students may prefer one class size to another based on their learning style and academic goals. Faculty should advise majors and potential majors to focus on smaller sections of courses in their major to develop the requisite higher order thinking skills.
Richard C. Schiming
