The objective of this dissertation was to evaluate a bystander behavior program at the Jefferson College of Health Sciences (JCHS) in Roanoke, Virginia. Specifically, this dissertation examined the: (1) preliminary measurement properties of a newly developed bystander behavior intention scale; (2) impact of the bystander intervention at JCHS; and (3) underlying processes that influence bystander behaviors. Approximately 25 percent of college students are in a physically abusive dating relationship (Miller, 2011). Bystander programs are one strategy to decrease dating violence and increase prosocial behaviors (Banyard, 2008; Banyard, Moynihan, & Plante, 2007; McMahon & Banyard, 2012). This is one of the first known studies to define bystander behaviors towards dating violence and evaluate a bystander behavior program that was designed to be less resource intensive for college campuses with limited time and funding. This dissertation used a quasi-experimental study design to evaluate the bystander behavior intervention at JCHS. The methods of concept mapping and cognitive interviews were used to develop the survey items (Beatty & Willis, 2007; Kane & Trochim, 2006). Internal consistency of the scale was assessed using Cronbach's alpha and exploratory factor analysis (EFA) to examine the factor structure. Difference-in-difference methods were used to evaluate the program impact (Wooldridge, 2009), and path analysis was used to examine the factors that drive bystander behaviors (DeVellis, 1991). First, the EFA identified that bystander behavioral intentions to prevent dating violence represented a uni-dimensional factor structure with strong factor loadings and internal consistency. Second, using the difference-in-difference method, results showed a positive increase in bystander behaviors before and after the intervention after adjusting for potential confounders. No significant changes were found for bystander intentions, self-efficacy, social norms, or attitudes pre- and post-intervention. Third, results from the multivariate path analysis model show that bystander intentions do not mediate the relationship between self-efficacy, social norms, and attitudes and bystander behaviors, as hypothesized by the Integrated Behavioral Model (Fishbein & Ajzen, 2010). However, results suggest that self-efficacy has a moderately strong direct relationship to bystander behaviors. These findings show that a less resource intensive intervention can increase bystander behaviors to prevent dating violence. However, more research is needed to understand the drivers of bystander behaviors, which will help programs target their interventions more effectively in the future. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]