Penny-wise Decisions

• By Paul Abramson
• 07/01/06

Dr. Sandra West, associate professor of Biology at Texas State University–San Marcos, was previously a high school science teacher. She has been looking at the relationships among class size, room space and reported accidents in high school science laboratories. Her research confirms two“common sense” concepts and puts some real numbers to them.

For example, national guidelines call for no more than 24 students in a high school science lab. She was concerned because, in Texas, her area of immediate interest, increasing student enrollment was pushing class size beyond 24. According to reports she elicited from teachers, when class size is 22 or fewer students in a lab, 27 percent of labs report having accidents of any type during a school year.

When class size is the recommended 24, Dr West found that accidents occurred in 36 percent of the labs, a significant increase. But when class size rose above 24, even by a single additional student, accidents occurred in 58 percent of the labs. As the number of students increases, supervision decreases and accidents are far more likely to occur. (Twenty-four students in a lab, many science teachers tell me, is already an overload. They consider 16 better for instruction and safer.)

It is not just the number of students but the space per student that is important. Based on our own observations, my firm has for many years specified 1,400 sq. ft. for a high school science lab, plus support space such as a prep room. As computers move into the labs, additional space should be provided.

But when plans are drawn, we often find that the space has been cut as a budgetary measure. Sometimes the district is committed to holding class size down (“we don’t need that much space because we never schedule more than 16 in a lab,” one superintendent told me), but budgets also affect that. When push comes to shove, additional students are often assigned to the undersized labs.

What happens when less space is provided? According to Dr. West’s research (based on reports from science teachers in Texas high schools), only 11 percent of all science lab accidents occur in rooms that provide 60 sq. ft. per student or more.

Twenty-three percent occur in science labs that provide 46 to 60 sq. ft. per student. In other words, reducing space by 15 sq. ft. or less per student is likely to double the number of accidents in a lab. Think of it this way: If a lab is 1,440 sq. ft. and it is scheduled for use by 24 students (24 @ 60 sq. ft. per student), adding just one additional student could result in twice as many accidents in that lab.

Many science labs are smaller than that. One common practice is to design science labs of 1,080 sq. ft. or 45 sq. ft. for each of 24 stations. Sixty-six percent of all science lab accidents occur when 45 sq. ft. per student or less is provided. So if you have science labs that are 1,080 sq. ft. and you schedule 24 students into those labs at any one time, you are six times as likely to have an accident as you would be if you provided 60 sq. ft. per student or limited classes in those small rooms to no more than 18 students.

Space costs money, and with the median high school in the United States now costing $150 per sq. ft., the temptation is to cut initial costs by reducing space. After all, if there are five science labs in a high school, and each can be reduced from 1,440 sq. ft. to 1,080, that’s a saving of $270,000 right off the bat. Use similar calculations for other instructional space, and the initial cost of a high school or an addition can be lowered.

But there are consequences to such penny-wise decisions. Dr. West’s research highlights a significant one — an increase in the incidence of science lab accidents, an increase that is likely to continue year after year after year, so long as the building is in use.

School buildings are expensive, and there is always public pressure to hold construction costs down. But those of us involved in planning and building them need to remember that these buildings will house and shape our educational programs for at least the next 50 years.