This investigation looks at the relationship between a STEM learning community's co-curricular activities and students' perceived sense of community (SOC) to determine which activities most influence SOC and, in turn, retention. This investigation shows that SOC can be impacted by a multitude of factors found within the college environment. The most influential of these factors are open acceptance, student academic support services, and residential experiences. Most importantly there were significant differences for African American students participating in the STEM learning community on the measures of SOC, retention, and being on-track in mathematics. Additional data suggested higher levels of being on-track in mathematics for male students and differences in retention and being on-track for Hispanic students participating in a STEM learning community. [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.]