School & District Management

Students Observed to Be ‘On Task’ Less as Class Size Grows

By Debra Viadero — April 01, 2008 3 min read
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A new British study quantifies and confirms what many teachers have long believed: Students tend to be “off task” more often when they are in larger classes.

The report, by researchers from the University of London Institute of Education, was one of several studies on the educational effects of reducing class sizes that were presented here last week on the first day of the annual meeting of the Washington-based American Educational Research Association. The March 24-28 event was expected to draw more than 15,000 education scholars from around the world.

Studies on class size have long suggested that elementary school pupils tend to learn more in classes of 20 students or fewer. The new papers, which were based on studies conducted in the United States and Hong Kong, as well as in Great Britain, extend and deepen the discussion on that topic by looking more closely at what goes on inside smaller and larger classes.

In his study of British classrooms, for instance, researcher Peter Blatchford found that both elementary and secondary students benefit from smaller classes, and that the benefits at the secondary level are particularly strong for the lowest-achieving students. That study involved 686 students in 27 primary schools and 22 secondary schools in Great Britain.

Benefits in Britain

The students were closely observed by teams of researchers who recorded their “moment to moment” behaviors in blocks of 10-second intervals. The researchers found that adding five students to a class decreased the odds of students’ being on task by nearly a quarter. In fact, the study found that low-attaining students were nearly twice as likely to be disengaged in classes of 30 students as they were in classes of 15.

“As class size increases, the amount of teaching also increases,” Mr. Blatchford, a professor of psychology and education, added. “But that’s explained by more whole-class teaching.”

Teachers are not necessarily capitalizing on the smaller settings to engage more students in collaborative projects—a finding that that some other studies have echoed. In secondary classrooms with low-achieving students, though, teachers are also spending more of their time dealing with pupils’ off-task behaviors, Mr. Blatchford said.

Contrary to some class-size studies conducted in the United States, the British researchers found no “threshold effect” in their study. In other words, classes did not have to be reduced to 15 or 20 students before the behavioral benefits started to kick in.

Reducing class size at any end of the class-size spectrum seemed to help.

Hong Kong Context

A second study presented at the conference, though, suggested that cultural differences can also play a role in the way that class-size differences affect learning.

Maurice Galton, an education professor from the University of Cambridge in Britain, has been studying the effects of an initiative to phase in reductions in primary-level class sizes over several years in Hong Kong. The schools there, as elsewhere in Asia, are noted for having larger classes than is typical in many Western nations.

In the 7,000-student Hong Kong study, the class-size reductions appeared to have no effect on the level of student engagement—mostly because students were already on task much of the time, according to Mr. Galton. He also found that teachers’ one-on-one interactions with students were just as frequent in classes of 20 to 25 students as they were in classes of 32 to 37 students.

Mr. Galton said that is because Chinese teachers typically make an effort to interact with each student, keeping track by ticking off the names on the class roster as they go along.

Teachers did spend more time talking with individual students in smaller classes, though, and their students were more likely to ask for help outside of class. Teachers in larger classes also relied more on textbooks for all of their instruction, the study found.

“We need to be able to collect data in different cultural contexts,” Mr. Galton said, “so we can tease out those things that are common and those things that are peculiar to that culture.”

U.S. Results Not Ready

The U.S. study, which was conducted by researchers from the University of Wisconsin-Madison, also attempts to focus on what goes on inside classrooms, rather than rely on measuring only outcomes, such as student achievement.

The study tracked schooling in nine Wisconsin schools taking part in that state’s Student Achievement Guarantee in Education, or SAGE, program. The initiative is aimed at reducing the pupil-teacher ratio to 15-to-1 in kindergarten to 3rd grade classrooms serving economically disadvantaged students.

Those findings are not due to be released by the state education department until this summer.

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