Do Larger Classes Necessarily Affect Student Learning?


Jim Horn argues against increasing class size. I suggest that class size may not influence student achievement as he and conventional wisdom assert.

Jim’s take that small classes are better seems consistent with conventional wisdom.

Studying influences of class size on student achievement is a technically complicated topic. The overlay of conventional wisdom, political biases, etc. appears to compound these complications.

About 12 years ago, a doctoral student (I have forgotten her name at the moment) at Illinois State University examined all 1,500 plus empirical studies reported in peer reviewed publications on the topic. About half of the studies reported differences, the other half reported no differences in student achievement.

After using sophisticated statistical procedures, she found that class size was not related to student performance, once the size exceeded about 15 students.

In other words, her findings appeared consistent with the impact of small groups on human performance.

Perhaps you know, I don’t, how many such meta studies about class size have been conducted and what their authors found.

In the long view, many technical alternatives exist today (such as electronic communications for individualized instruction) to mitigate whatever affects (not effects) class size may have on the learning rate of an individual student.

Kudos to teachers who emphasize these alternatives. I wonder how I’d design a study to test the affect of mitigations of class size on learning rates of various ages of students?

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Robert Heiny
Robert W. Heiny, Ph.D. is a retired professor, social scientist, and business partner with previous academic appointments as a public school classroom teacher, senior faculty, or senior research member, and administrator. Appointments included at University of North Carolina at Chapel Hill, Peabody College and the Kennedy Center now of Vanderbilt University; and Brandeis University. Dr. Heiny also served as Director of the Montana Center on Disabilities. His peer reviewed contributions to education include publication in [I]The Encyclopedia of Education [/I](1971), and in professional journals and conferences. He served s an expert reviewer of proposals to USOE, and on a team that wrote plans for 12 state-wide and multistate special education and preschools programs. He currently writes user guides for educators and learners as well as columns for [I]TuxReports[/I].com.


  1. Note: I’m looking at this from a higher education stand point. A class is not a “large class” as long as the room it’s taught in can hold, oh, 1.3x (or more) the number of students enrolled in the class AND as long as the teacher takes advantage of technology such as projectors (and microphones for a class greater than 50 people). My university is a public one with over 45000 people. That makes for many large classes. What makes a good class? Let me walk you through two very different situations:1) My chemistry class with 430 people I had no problem with at all. I could walk in, sit where ever I felt comfortable, and hear and see what was going on thanks to two huge projectors. I could keep up with the lecture and bad eye sight never hurt my productivity. 2) My mechanics of solids class has 100 people. It’s taught in a long thin room with cramped lecture seats, no lefty-desks (I’m a lefty), and is 100% full when everyone shows up to class. If I show up later than five minutes before the bell, I must sit in the back, a good 40′ from the board. The professor doesn’t use a microphone, speaks softly, and uses chalk on a chalkboard as his only means of communicating visually.Class 1 succeeded with a large number of students because there was plenty of seats and proper use of technology to accommodate. Class 2 failed miserably and I have no clue what’s going on half the time because they simply crammed a bunch of students in a small class setting. In other words, there’s a right way and a wrong way to have bigger classes. I only hope those who encourage bigger classes know this. As for letting the good teachers teach larger classes, I’m all for it. A good teacher makes a world of a difference in a class as long as the items mentioned above are thought of first.

  2. Thanks for your thoughtful comment, Tracy. You pleasantly provoked more thought about the importance of class sizes. I appreciate your style. I recognize the kinds of settings you describe, including the faculty members’ performances (yes, faculty must act in order to speak to the back row of any class; such performances are more “natural” for some of us than others). I’m an alum of smaller class enrollments PreK thru doctoral study. I have offered university classes in lecture halls with enrollments in some courses up to about 125 students. I’d suggest that class size is an available, but relatively unimportant variable impacting student learning rates and achievement. Education policy analysts use class size as a variable because it is easy to obtain and to test an aspect of conventional wisdom. As a student and later as a faculty member, student initiative seems at least as important as class size in influencing student achievement. But measuring student initiative is difficult at best. Its empirical indices have fatal flaws. So, scientists use proxies, including class size. I like your inference that faculty initiative to use a strong (or amplified) voice, projectors and other communication devices (dare I add Tablet PCs) is measurable and as important as the number of people in a room. Technically, I don’t understand the common reference to “good teachers.” It seems to me that such references misdirect attention from an individual’s learning, the traditional purpose for schools. Respectfully, ultimately, what a student learns rests with the student. A teacher and other variables may make learning easier, but probably do not necessarily over ride student initiative and preparation. You’ve prodded me to think about “good teaching” and similar variables some more.