New NIH resource for studies that randomize groups or clusters or that deliver interventions to groups

Experiments, including clinical trials, differ in the methods used to assign participants to study conditions or arms and to deliver interventions. Thanks to the Office of Disease Prevention, the NIH has a new website that provides resources on research methods related to experiments that randomize groups or clusters or that deliver interventions to groups. The information is relevant for human and animal studies and for basic and applied research. The website includes a calculator to estimate sample size requirements for group- or cluster-randomized trials.