Sociability is an environmental characteristic of online learning that is perceived to facilitate social interactions. Compared to face-to-face learning environments, online learning has been criticized for being “less” social. In an attempt to increase the sociability of online learning, this chapter reports two studies that were conducted to examine the impacts of (a) the size of discussion groups and (b) the use of supplementary social network sites in asynchronous online graduate courses. In the first study, the sociability of small group discussions versus whole class discussions was compared. The results indicated that when in small group discussions, students perceived a higher level of sociability, t (32)= 3.507, p< 0.001. In the second study, findings indicated that students who participated in a supplementary Facebook group, in addition to the regular academic activities in the learning management system, felt a higher level of sociability, t (32)= 6.804, p< 0.001. Design decisions can influence social affordances in online learning, leading to an increase in students’ feelings of connectedness with others and instructors. The implications of the study include design guidelines for asynchronous, text-based discussions and the use of social network sites in online learning.