Does a well-designed preschool classroom have plenty of artwork, learning charts, and motivational posters up on display? Is warm lighting cosier? Are smaller learning groups always better? The answers—based on research—may surprise you.

Find out what environments are most conducive for your preschool child to learn.

Loud Walls Can Be Distracting

If Pinterest is any indication, a respectable preschool classroom should be adorned with artwork, learning charts, and positive messages for kids. But did you know that these elements can be visually distracting for young children?

In a 2014 study by Carnegie Mellon University, researchers placed 24 kindergarten students in two classrooms for six science lessons—three lessons were conducted in a heavily decorated classroom, and three lessons were held in a sparse classroom. Upon testing the students, the researchers found that the students from the sparse classroom performed better (55% correct answers) than the students from the decorated classroom (42% correct answers).

The researchers also estimated that the rate of distracted behaviour was higher in the decorated classroom, compared to the sparse classroom.

The takeaway for parents: don’t write off a preschool with clean walls, as you may have found a winner!

Choose Daylight Or Cool Light

Can increased exposure to daylight in a classroom help with academic performance?

In a study conducted nearly two decades ago, an energy consulting group analysed test scores for 21,000 students in three US elementary school districts. In one of the districts, students with the most daylight in their classrooms were found to progress faster on math and reading tests, compared to those in classrooms with the least daylight.

If the preschools on your shortlist don’t have natural lighting features, you can also look for classroom environments that use 6500K lighting—a cool, bluish white light modelled after daylight. A 2016 South Korean study of 54 fourth-grade students found that the students were more alert and scored higher on tests when they were in a classroom with 6500K lighting.

Go Green

If you’ve ever felt rejuvenated after a walk in the park, rest assured that it’s not all in your head. Research has shown that even the act of watching a nature documentary or looking at a computerised nature image can improve one’s mood and ability to focus on a task. And at least one study has found that students with “higher exposure” to greenery displayed better performance in English and Math.

To let your child reap the benefits of nature, look for a preschool situated in or near a green space. For maximum exposure, check that your child’s classroom offers a green view from the window, or, at the very least, a view of leafy indoor plants.

The Best Temperature For Learning

Some parents prefer to avoid air-conditioned learning environments for their children, and their concerns are valid—contaminated AC units could aggravate the conditions of those already suffering from asthma or allergies.

For those who are not adversely affected by AC exposure, the recommended temperature range for indoor spaces in Singapore is 22.5 to 25.5 deg C. According to Nilesh Jadhav, a senior scientist at the Nanyang Technological University, this is the temperature that lends itself to a comfortable and productive environment.

However, the best gauge of a classroom’s desired temperature would be your child and his or her peers. If students are too warm or too cold, they may feel tired and lethargic, or simply too uncomfortable to focus on learning.

Class Size: Smaller Isn’t Much Better

If you’re thinking of splurging on a playgroup or preschool that keeps class sizes small, you may want to consider your options carefully.

An analysis of nearly six decades’ worth of early childhood research found that only child-teacher ratios of 7.5 to 1 or lower were linked to benefits for children, and that these benefits were statistically significant but not large. The study concluded that class sizes at or below 20 and child–teacher ratios at or below 10:1 “are largely adequate for most children.”

“If you’re within what is typical, we do think reducing class sizes by small amounts is not going to gain you much in terms of results,” says the study’s lead author Jocelyn Bonnes Bowne. However, she concedes that her study did not focus on the impact of class size on high-needs students, such as those from disadvantaged backgrounds.

Note: Currently, Singapore’s child-staff ratio for kindergartens is capped at 25 children to 1 teacher, or 30 children to 2 staff.