After nearly two years in development, a new federally backed research service on "what works" in education began rolling its first products off the assembly line. Launched with $18.5 million in funding from the U.S. Department of Education, the newly operational What Works Clearinghouse is the department's electronic version of a "Consumer…

Beginners in many disciplines learn that correlation never proves causation, but sometimes, even in public health, correlation, mistaken for causation, becomes the basis for policy and great expenditures of public and private money. "True experiments" with random assignment to experimental and control groups hold a special place in the…