In 2002, the Women's Health Initiative, a large-scale study of the safety of hormone replacement therapy (HRT) for women conducted in the United States, released results suggesting that use of postmenopausal HRT increased women's risks of stroke and breast cancer. In the years that followed, as...

A randomized experiment of Comer's School Development Program was conducted in 23 middle schools in Prince George's County, Maryland. It showed that Comer schools implemented some of the program's central elements better than control schools, but not all or even most of them. This shortfall in...