Michael Hansen, a senior researcher at the American Institutes for Research, just published Right-sizing the Classroom: Making the Most of Great Teachers. Hansen examined data from North Carolina to determine the relationship between teacher effectiveness and student assignment/class sizes.
Dr. Hansen found,
- North Carolina appears to differentiate class sizes based on teachers’ performance only to a very limited extent.
- The results show that relatively minor changes in the way that students are assigned to teachers can lead to significant learning gains. But the size of these gains depends on grade level, with eighth grade more promising than fifth grade.
- Results show that the class-size-shifting strategy shows an overall improvement in student access to effective teaching, yet gaps in access for economically disadvantaged students persist.
Can student learning improve by simply reallocating the distribution of students among teachers? The results of this investigation say yes, though the extent of the achievement gain—and the price tag—depend on grade level and a suite of human-resource policy decisions. Perhaps most important, this analysis makes clear that universally shrinking class sizes may be counterproductive in terms of pupil achievement— and that purposefully expanding some of them can be more efficacious.