Alcohol use among college students has maintained its place as a major issue in American higher education since its inception. Although dangerous drinking has always proliferated among college students, institutions have only provided alcohol and other drug (AOD) education and interventions encouraging students to adapt less harmful habits for a much shorter period of time. During this relatively short history of postsecondary alcohol interventions, colleges and universities have shifted away from abstinence-only, education-based methods. Instead, institutions have begun to adapt cognitive behavior-centric, motivational enhancement-based strategies emphasizing harm reduction through the use of protective behaviors. In order to reach a greater number of students, alcohol intervention programs have been developed combining the harm reduction ideology with internet-based dispersion at a population level. This research study addressed the behavioral changes that occurred among an entire class of first-time-in-college freshmen at a large public university before and after mandatory participation in AlcoholEdu for College, an online, population-level, harm reduction-based alcohol intervention. The study expanded upon previous evaluations of the program, which addressed program efficacy among the population as a whole but did not further explore differences in effect upon students engaging in different levels of drinking. Other demographic factors, such as gender, ethnicity, family history of alcohol issues, and age of first consumption, were also taken into account. Pre-test surveys taken by students prior to the intervention at the beginning of the academic year were matched to follow-up surveys taken four to six weeks after program completion, providing the necessary data for conducting a quantitative study. The specific areas of interest within the study included (a) willingness to complete the program in a timely and complete fashion, (b) levels of consumption, (c) use of protective behavioral strategies (PBS), and (d) incurrence of negative alcohol-related consequences. A combination of analytical procedures was utilized, including descriptive statistics, chi-square tests for independence, exploratory factor analysis, repeated measures ANCOVA, and nonparametric inferential tests. Results were described within the framework of social cognitive theory (Bandura, 2004) as well as the CIPP program evaluation framework (Stufflebeam & Shinkfield, 2007). The analysis uncovered that three major factors determined willingness to complete the mandatory program in a timely and complete fashion: gender, age of first alcohol consumption, and drinker group. Specifically, students who were male, started drinking prior to high school, or were identified as heavy episodic drinkers were less likely than peers to complete all portions of the AlcoholEdu program. Both moderate and heavy episodic drinkers reduced their levels of consumption between pre-test and follow-up. A large percentage of abstaining students maintained this status later in the semester. Light and moderate drinkers either maintained or slightly reduced their use of PBS, while heavy episodic drinkers showed increases in use of most types of PBS over time. All students indicated low levels of incurrence of negative consequences in both the pre-test and follow-up periods. However, while students experienced an increased number of most of these consequences between the pre-test and follow-up surveys, heavy drinkers cited a decreased rate of drinking and driving-related consequences as of the follow-up. Throughout all of the analyses, important controlling factors included gender, ethnicity, and age of first alcohol consumption. The results of this study can guide future development and refinement of the AlcoholEdu program, as well as provide higher education administrators and AOD education program staff with additional baseline knowledge of the change process first-time-in-college freshmen undergo when engaged in the program.