Convenience sampling selects a particular group of people but it does not come close to sampling all of a population. Researchers want to study the effectiveness of a diversion program for preventing further criminal activity among first-time juvenile offenders. Many cities across the nation have such programs but the researchers study the program in their city. The sample would generalize only to similar programs in similar cities. Convenience sampling is widely used in student research projects. Students contact professors that they know and ask if they can use their classes to recruit research subjects.