Smaller class sizes may reduce performance gaps in science courses, according to a new study from The University of Minnesota.

The research suggests that some performance gap issues could be amended with improved policy development and legislative action at the university level.

The research is published in the journal BioScience.

Examining students

To conduct the study, the researchers collected data from 17 introductory biology courses from four universities: California State University, Chico; Cornell University; University of Puget Sound; and the University of Minnesota Twin Cities.

They collected exam grades, non-exam assessments of student knowledge (i.e., laboratories, online activities) and final course grades from more than 1,800 students.

The minimum class size surveyed was 40 students, while the maximum class size was 239.

Then, the researchers analyzed the data by comparing the performance levels of women and other underrepresented minorities to those of men and students form well-represented backgrounds in both small and large classes.

The findings

The researchers found that while female students underperformed on high-stakes exams compared to men as class size increased, they received higher scores than men on non-exam assessments.

They also found that, in general, smaller class sizes closed the gender gap in academic performance between men and women.

“We suspect that the student experience in small classes is totally distinct from the large class learning environment. Students likely have more opportunities to interact with the instructor personally and through in-class interactions, a stronger sense of community among students, and increased engagement with the material. Students can’t just kick back in the last row of a lecture hall when they are one of forty people in the classroom,” said Cissy Ballen, a postdoctoral associate in Biology Teaching and Learning and lead author on this study.

But smaller classes did not impact underrepresented minorities, who underperformed compared to students from well-represented backgrounds, regardless of class size.

This suggests that the impacts of class size do not generalize to all students, and that there are other characteristics of the education environment that affect learning.

However, the researchers maintain the idea that these results may be of interest when it comes to future policy-making decisions.

“While many variables contribute to student performance, these results may be compelling for administrators, curriculum committees or legislators who are motivated to promote all undergraduate scientists,” Sehoya Cotner, an associate professor of biological sciences and senior author of the study, said in a statement.

Future studies  

The researchers are currently collaborating with a number of faculty members to replicate their current analyses across different science disciplines.

“A lot of research has documented how students struggle in disciplines in which they have been historically underrepresented, even when controlling for their incoming academic preparation for the class. This means something other than students’ ability to understand course material is hindering their ability to learn, such as a negative classroom atmosphere,” said Ballen. “If reducing class size benefits students because it improves the classroom social climate, we would expect to see the same results regardless of discipline.”

Additionally, Ballen said that they will be initiating a number of projects to focus on different elements of classroom and university environment that influence student performance.

“Future work will test a number of evidence-based in-class strategies across STEM disciplines and institution types, all with the goal of promoting equity in STEM learning environments,” she said.