In my book I reference the class size research of Peter Blatchford as an example of research too focused on test scores:

Far too many studies seem to assume (perhaps rightly) that policymakers will snicker at discussions of attitude, morale, or emotional well-being. Hence, most research on class size reduction centers unflinchingly on test scores. Nonetheless, Blatchford himself noted, “It may be that a smaller class size allows a teacher to approach children in a more personalized and more humanistic way, but this would be hard to measure and then enter into statistical analysis!” (2003, p. 160). The exclamation point is his. Other researchers have made similar comments as postscripts to their studies, for example:

It should be noted that these enrichments to the curriculum may not be reflected in evaluations of class-size effects. Typically, achievement tests in reading and mathematics are used to evaluate outcomes. This narrow definition of achievement overlooks learning in other academic areas, areas which may be valued by consumers of education. Also, many of the enrichment areas are intended to promote positive attitudes, enthusiasm, and overall learning skills. These factors may have long-term effects not in evidence on short-term achievement tests. Research in education may be misled by its focus on short-term achievement outcomes. (Cahen et al., 1983, p. 206)

Nevertheless, most research continues to be misled in this way and to make only minor acknowledgments of the possibility. (pages 123-124)

Kudos to Peter Blatchford! Turns out he has followed up on this acknowledgment (since my book researched had stopped) and began to do class size research that looks inside the black box rather than simply looking at the easily measurable outputs from that box.

There has been a tendency to assume that links between class size and academic attainment are primary, and that links with classroom interactions are secondary. But it is important that pupils engage in work in classrooms and important that interactions with teachers are work focussed and where possible individualised, irrespective of whether we can show that these obviously cause changes in measured test scores. The quantity and type of interactions with teachers, and the degree of attention in class, are therefore important ‘outcomes’ in their own right.

(Do low attaining and younger students benefit most from small classes? Results from a systematic observation study of class size effects on pupil classroom engagement and teacher pupil interaction Peter Blatchford, Paul Bassett and Penelope Brown, 2008,  p. 24)

Let me note from the outset that the subjects were British and that there is no disaggregation by race or other possibly significant cultural factors. The paper finds some common sense results like the fact that individual interactions with the teach skyrocket (exponentially):

Similar results are found for pupils being the focus of the teacher’s attention. (There’s a book about that!) Meanwhile, time on task rises more linearly:

When the data is disaggregated by student achievement level, there are some stunning results suggesting that it is the low and mid achieving students who need the teacher’s attention (as indicated by off task behavior) and the highest achieving that seem to just need the teacher to get out of their way. The irony is, of course, that the highest achieving students are often tracked into (or their parents pay their way into) exclusive programs and schools with smaller class sizes!

elementary:

secondary:

Similar graphs depict how likely it is that teachers spend time on negative behavior with students from each achievement level. (Curiously, the researchers do not report the aggregate correlation between class size and their “teacher deal with negative behaviour” coding.) That high and medium actually go down with larger class size might reflect that teachers simply opt to let higher achieving kids get away with more and focus on reigning in the lower achieving kids. I describe this in the book as a process where in larger classes teachers tend to divide the class into allies and adversaries. The researchers write,

We feel that these results on on and off task behaviour are significant because they show that the problem of large classes, especially in older pupils, is particularly marked for the pupils who are already attaining at lower levels, and that it, in turn, is associated with teachers seeking to control this kind of behaviour. It is easy to see how these two kinds of behaviours can become self reinforcing, exacerbating each other and making the situation worse. In contrast, smaller classes seem to allow an environment in which low attainers are not only less off task but are less likely to receive corrective talk from their teachers. This appears to be a more productive educational environment. (23)

And then there are results that are ambiguous in import. First, there is less student-to-student interaction as classes get smaller, whether its on or off task interaction. “It seems likely that with more pupils in the classroom there is less of the teacher’s individual attention available and this presumably means that pupils come to interact more with each other instead, in both acceptable and unacceptable ways” (23). My response to this would be that (a) we probably need to remind and train teachers to keep doing group work in small classes, and (b) we need to make sure not to glamorize peer cooperation that is out of balance with adult attention. (See chapter 4 of my book.)

Second, teachers appear to spend less time actually “teaching” the class in the traditional sense. According to the researchers, “in smaller classes pupils get more individual attention, while in larger classes they spend more time listening to the teacher talk to the whole class. They are perhaps getting more educational input, but this is at the expense of it being largely passive and as part of a large group” (22).

elementary:

secondary:

This could perhaps explain why the test scores don’t skyrocket in the same way other indicators do. Perhaps teachers can accomplish the same amount more efficiently and don’t necessarily feel the need to make small classes learn more just because they could. The “more! better! faster!” discourses we have been bombarded with would say these teachers are being lazy, are squandering the opportunity to beat the [fill in competitors here]. I plan to focus my doctoral research around questioning this response. Why more? Why better? Why faster? Instead, I want to propose that more equal is the only real urgency. And Blatchford, Bassett and Brown’s research suggests that more equal (as opposed to better than)  is precisely the tendency inherent in class size reduction.