August 21, 2008

Why Class Size Matters

After the American Century

As universities and secondary schools and primary schools begin the new academic year, once again there are stories in the press about class size. In Denmark, some schools have pressed up the number of students to 30 in a room, and such class sizes can also be found in some parts of the US. Now anyone can see that the more students there are, the more work there is for the teacher, in terms of grading papers, exams, and reports. But actually, this is not the main problem with the larger classes.

After teaching for more than three decades, I think I have some insight into why class size matters. First, the larger the class the less each student can participate. If there are 30 students in a class that meets for one hour, given equal time, each of them can only speak for two minutes. In a language class, for example, that means students will speak so little that they will not improve. Furthermore, as all teachers can tell you, once there are 30 students, it becomes almost impossible to get all of them to participate equally. Rather, a smaller number will do more of the talking, and some will sit silently most of the time. Class participation matters because it gets students thinking. As soon as a student expresses an idea it must be defended, explained, compared to other positions, and so forth. The quiet student is far less likely to get engaged in discussions, and less likely to develop thoughtful positions.

A second reason class size matters is due to the internal dynamics of the group. Consider a class with just two students. There is only one relationship for each, two in all. Add one more student, and there are suddenly six relationships, two for each. Add a fourth student, and each of the four students has three relations, a total of 12. In other words, the social complexity of a class increases geometrically. By the time there are 30 students in a room, each of them has 29 relationships, not to mention cliques, clusters, and groups. A teacher can keep an eye on 15 or 20 students and maintain a sense of the various dynamics of the room, but the task becomes immensely more difficult as each new person is added. Speaking for myself, somewhere between 22 and 24 students the class gets too large for a comfortable, open dynamic. Consider that 22 students, who collectively have 462 potential relationships. A politician with no teaching experience may think it does not mean too much to add eight more students, but in fact the social complexity of what is going on almost doubles, to 870 potential relationships. At this point, few teachers can keep track of the internal dynamics in a class. More importantly, the students themselves cannot keep track of them all. A class is no longer comfortable, but unpredictable. It ceases to be a open context, and many decide to keep their heads down. Teachers find it necessary to do more and more of the talking as class size rises. Once larger than 30, it becomes hard to avoid turning the lesson into a lecture.

These two reasons ought to be enough, but there is one more. The larger the class gets, the more stressful teaching becomes, assuming that the teacher wants to keep a dialogue alive with the students. As the numbers grow, it becomes harder to remember student names and their individual problems, and students immediately sense this and of course resent it. As classes grow, teachers find it hard to create and maintain a bond. Disruptions and disciplinary problems become more frequent. Teachers caught in that situation year after year may leave the profession. Some will think it is their own fault, but foolish politicians who are "optimizing resources" are the culprits.

When you hear about classes being larger than about 24, you can be sure the educational process is in danger. When class size rises to 30, the politicians who have imposed this "savings" should be replaced as soon as possible. One final illustration suggests you should believe these observations. Look at elite private schools that cater to children of the rich. They have the choice to do whatever works best, and without exception they keep classes small.