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What is the effect of class size on student learning?

The following summarizes the findings of a report entitled "A Study of Class Size and its Effect on Learning." Results of the study conducted by the Alberta Teachers' Association were presented to the Alberta government and distributed to school boards across the province. School councils wishing to obtain a copy of the full report should contact David Flower at (780) 447-9422.

The debate over class size has been waged in Alberta for decades. It came to the fore in 1980 during the Calgary public teachers' strike and was the subject of a recommendation of the Kratzmann Report (the Kratzmann Commission was created to investigate the 1980 Calgary strike and to make recommendations). The issue of class size has again become the subject of debate thanks to the many attempts in the U.S. to reform the public education system.

Teachers' view of class size has always been clear. Teachers believe that smaller classes "provide better quality and a richer environment for pupils, while making teaching more enjoyable for the teacher."

Substantial research has been conducted in the U.S. on class size. Although most of the studies have attempted simply to use test results as a measure of the effectiveness of class size, there does appear to be some consensus on the following three points:

  • smaller class sizes result in higher achievement among students who are economically disadvantaged
  • smaller class sizes result in students with lower academic ability doing better
  • class size might affect student attitudes more significantly than it affects achievement.

The most documented study of the effect of class size is the Tennessee STAR Project (Student Teacher Achievement Ratio). This study found that classes of fewer than 17 students to one teacher are most effective. The latest research (April 29, 1999) states, "students in smaller classes outperform their peers in larger classroom settings." The 10-year Tennessee study shows that "students in classes of 13 to 17 have better grades, higher graduation rates, and are more likely to attend college."

The research findings, while suggesting that teachers and parents support lower class sizes, also point to the fact that in order to achieve maximum impact "class-size reduction should be used in conjunction with other strategies." These would include a review of teaching methods, classroom management and inservice training. Simply reducing class sizes with out having sufficient qualified teachers, or not reducing class size enough to have a clear impact, simply does not make a difference.