Raising Student Test Scores May Be As Simple — And Cheap — As Opening A Window

A solution to falling student test scores might be right under our noses.

Air quality in schools has a direct effect on pupil performance, according to recent research from MIT’s Center for Real Estate Research, University College London and Maastricht University.

The two-year study, conducted 2018-2020 in the Netherlands with students aged 5 to 13, monitored carbon dioxide levels in classrooms and collected data on student test scores. The results were clear: the higher the CO2 levels, the lower the scores on standardized tests.

“Poor air quality is a widespread issue that seems to affect the bulk of the student population,” MIT’s Juan Palacios, one of the study’s authors, told Forbes.

The numbers, in fact, looked familiar to researchers. Higher concentrations of CO2 coincided with a 0.11 standard deviation decrease in test scores — roughly the same decline observed in students after remote learning during the pandemic.

Improving classroom ventilation holds the promise of raising student performance in the $800 billion U.S. educational system without spending much money. In a 2012 experiment in Tennessee, researchers were successful in boosting scores by the stated goal of 1% of a standard deviation by adding more teachers and reducing class size. That method cost $163 per child per year. By contrast, more oxygen — as simple as cracking the windows, cleaning vents, changing filters and properly maintaining HVAC systems — cost about $42.

The U.S. spends about $16,000 per public school student per year, with about $1,500 of that going to infrastructure, according to the National Center for Education Statistics.

Previous research is harmonious with the findings. A 2011 study cited by the authors measured how poor ventilation impacted students’ performance on attention, concentration and memory tests. A 2017 review of existing research concluded that adequate air flow contributed to better performance and fewer absences. But the authors of the latest study say theirs is the first look at how air quality directly affects educational outcomes.

The study has not yet been peer reviewed, but its protocol received a seal of approval from other researchers before the research was conducted.

“We compared the effect sizes with other interventions done in the past,” Palacios told Forbes. “What we see is that improving air quality gives equivalent effects, but in terms of cost effectiveness it’s much cheaper. It seems like low-hanging fruit.”