Editor's Letter.

Clinical trials are the gold standard in study design for evaluating the benefits and harms of interventions. The National Institutes of Health defines a clinical trial as "a research study in which one or more human subjects are prospectively assigned to one or more interventions (which may include placebo or other control) to evaluate the effects of those interventions on health-related biomedical or behavioral outcomes." In other articles, B Amanda Hering b and B Daniel Cooley b tell us about the two-decade history of a group of statisticians at the National Center for Atmospheric Research (NCAR). [Extracted from the article]