A 13-member panel was convened by the National Institutes of Health in 2004 to look for consensus on causes of youth violence and ways to prevent it. Its conclusion was that "boot camps and other get-tough programs for adolescents do not prevent criminal behavior, as intended, and may make the problem even worse."4 Was their conclusion most likely based on one observational study, several observational studies, an experiment, a sample survey, or anecdotal evidence?