The University of Nottingham study examined whether the possibility of punishing free-riders leads to better group results.

VOA: special.2009.03.03

It is called LaserFest. The American Physical Society, the Optical Society ,and SPIE, a group that supports the study of light, all have been involved.

VOA: special.2010.09.01

Seventy-four people in the placebo group became infected during the study.

VOA: special.2009.10.13

The Principal Financial Group announced the results of the study.

VOA: special.2010.10.12

"An empowered group of ministers has been set up to study whether any changes in the law are necessary.

VOA: standard.2010.06.10

But study author Kristine Funk, the Kaiser Permanente Center for Health Research says those averages mask significant differences within the group of website users.

VOA: standard.2010.07.30

"Compared to the most active group of women." During the study, the average weight of the participants went up by six pounds, or 2.7 kilograms.

VOA: standard.2010.03.30