A real-life test of full-spectrum lamps in a local restaurant found no support for the idea that full-spectrum light changes diners' behavior, according to a new report issued by the Cornell Center for Hospitality Research.

Noting the assertion that full-spectrum lighting is more attractive to restaurant guests, the authors changed the lamps in the main dining room of a popular casual dining restaurant. Their idea was to test the notion that full-spectrum light changes people's behavior.

"What we found, though, is that sales didn't change when we put in the full-spectrum lamps," said Stephani K.A. Robson, a senior lecturer at the Cornell's School of Hotel Administration, who co-authored the study with Sheryl E. Kimes, professor at the Hotel School. "We think more study is needed, and we cannot rule out possible effects of full-spectrum light. But for the moment, we caution restaurant owners to save their money, rather than purchase expensive full-spectrum lamps."

The manipulations in the restaurant's lighting were intentionally subtle, because the researchers did not want to interfere with operations and did not want to call attention to the lighting alterations. The changes in the main dining room apparently went unnoticed; no guest commented, and average checks and dining duration did not change substantially after the lamps were altered.

On the other hand, sales in the restaurant's second dining room, the experiment's control room, increased during the test. Consequently, the researchers concluded that something else was at work in terms of changes on restaurant sales. For that reason, they suggest designing additional experiments to test the effect of full-spectrum light.

The report, "Examining the Effects of Full-spectrum Lighting in a Restaurant," is available at the center's Web site at http://hotelschool.cornell.edu/research/chr/pubs/reports/2007.html.