A study conducted for the Pacific Gas & Electric Co. and the California Board for Energy Efficiency has concluded that students perform significantly better if their classrooms are lit with natural, rather than artificial, light. The study, one of the largest of its kind, tracked test scores for 22,000 students in California, Colorado and Washington.

• The researchers report that learning rates were 26 percent higher in reading and 20 percent higher in math in rooms with the most natural light.

• The trend over the past 20 years has been toward artificially-lit classrooms, on the theory that windows in schools create a distraction for children.

• In an earlier study it was reported that students in a natural-light school in Wake County, N.C., posted the highest attendance rate in the country.

• A companion study looked at the effects of natural light in 108 stores in a large retail chain and found that those with skylights sold an average of 40 percent more merchandise than those without skylights.

The findings add credence to arguments long espoused by scientists and mental health experts that light plays a key role in helping people to be more productive, learn more and feel better.

Previous research -- much of it conducted in Europe and Canada -- has suggested the benefits of natural lighting, but none of those studies was as extensive as the California research.

Source: Andrea Billups, "Study Sheds Light on Why Some Pupils Are Bright," Washington Times, July 4, 1999.