Community trials address the efficacy of preventive interventions applied at the group level (e.g. , a social marketing campaign trial).A clinical trial is a research study that involves people. Clinical trials are scientific studies using human volunteers that determine the effectiveness, safety and tolerability of an intervention. A clinical trial is a research study in human volunteers to answer specific health questions. Each clinical trial has benefits and risks. Before you decide to be in one, you need to have all your questions answered. The transformation of clinical trials at Michigan Medicine is one of the top five goals for the Great Minds, Greater Discoveries strategic research plan. In randomized controlled trials (randomized clinical trials), researchers divide people into groups to compare different treatments or other interventions. In clinical trials, volunteers participate in studies of medical treatments.