A theory in quantitative research explains and predicts the probable relationship between different variables. Theories develop from researchers over time. For example researchers test the relationship that peer groups have an influence on adolescents. This relationship is tested over and over, such as with the Boy Scouts, in church groups, in middle schools. In sports teams, and other setting. Repeatedly the relationship of a positive effect holds true. In light of all this evidence, someone calls this relationship a theory and assigns name to it. “Smith’s theory of peer in fluence " is born, reported in the literature, and tested further by other researchers. Other examples of theories include a theory about how students learn, a theory about what motivates people a theory about leadership styles, and a theory about personality.