“Collective efficacy” describes the willingness of residents to work together in actions that improve residents’ safety and their common environment. “Social cohesion,” which is the foundation of collective efficacy, describes how residents think and feel about their neighborhood and their neighbors. Positive feelings facilitate interactions through conversation, helping one another, and organizing and cooperating for the common good. The National Institute of Justice (NIJ) and the Children’s Trust of Miami-Dade County, FL, sponsored a study that examined the features of collective efficacy. Eight ethnically and economically diverse Miami neighborhoods with differing crime rates were examined to determine the relationship between residents‘ perceptions of collective efficacy and social cohesion as well as their perceptions of neighborhood conditions, their confidence in the police, and their fear of crime. Researchers analyzed these relationships within and between neighborhoods. Based on the research findings, researchers propose steps to prevent crime and strengthen neighborhoods. These include investing in research and evaluation that examines residents’ concerns and their willingness to partner with public agencies and neighborhood residents to improve the neighborhood’s quality of life. The research data can then be used by stakeholders to identify problems, design solutions, and assess the effects of various problemsolving efforts. Other recommendations are to provide and improve public spaces, such as parks, where residents can interact with one another and organize the community for action while encouraging volunteerism for the common good.