Washington, Feb 29 : While shrinking the number of students in a class can lead to higher test scores overall, it might not necessarily reduce the achievement gaps that exist between students in a given classroom, a Northwestern University study suggests.
The study investigating the effects of class size on the achievement gap between high and low academic achievers appears in the March issue of Elementary School Journal.
"While decreasing class size may increase achievement on average for all types of students, it does not appear to reduce the achievement gap within a class," said Spyros Konstantopoulos, assistant professor at Northwestern's School of Education and Social Policy.
The researchers worked with data from Project STAR, a landmark longitudinal study launched in 1985 by the State of Tennessee to find out whether small classes had a positive impact on the academic achievement of students.
The researchers found that on average small classes had a positive impact on the academic performance of all students.
However, they also found that that the kids who already were high achievers were the primary beneficiaries of the extra attention smaller classes afforded.
"It is likely that high achievers are more engaged in learning opportunities and take advantage of the teaching practices that take place in smaller classes, or that they create opportunities for their own learning in smaller classes," Konstantoupoulos said.
"Given that class size reduction is an intervention that benefits all students, it's tempting to expect that it also will reduce the achievement gap," he added.
However, previous studies have not provided any evidence that class reduction benefited lower-achieving students more than others. The current study underscores that research.
The new suggest that small classes produce significantly higher variability in achievement than regular classes in kindergarten mathematics and in first grade reading.
Overall the findings indicate that class size reduction increases not only achievement for all students on average, but the variability in student achievement as well.