This qualitative case study sought to explore the social construction of knowledge in the Change My View (CMV) subreddit online community. Few of the prior studies of discussion in online courses found evidence of the higher Phases of knowledge construction (up to four and five of the IAM framework), and it was hoped that the CMV environment would facilitate the occurrence of those higher Phases, such as the co-construction and application of meaning. Two research questions were investigated: "To what extent were higher Phases of knowledge construction identified in the body of CMV?" and "What were the facilitating factors for knowledge construction reported by CMV members?" Two types of data were collected to understand multiple aspects of CMV. Ten discussion threads were analyzed and 37 responses gathered to an open-ended questionnaire about experiences in CMV. Five findings were revealed after conducting deductive content analysis with the threads' data and inductive content analysis of the questionnaire data. The key findings were: 1. There was evidence of all five Phases of knowledge construction in varying amounts (Phase 1 = 10.4%, Phase 2 = 28.4%, Phase 3 = 50.5%, Phase 4 = 8.3%, and Phase 5 = 2.4%); and 2. The factors of the CMV environment that were reported to foster knowledge construction were related to community structure (i.e., strict rules, the delta system, heavy moderation, anonymity, and interface notification features) and factors related to community discussions that are diverse, evidence-based, civil, safe, purpose-based, and providing immediate feedback. The study's other conclusions included that the IAM framework is applicable to study knowledge construction, but it needs an argument-based environment. Furthermore, four pillars of design features (motivation, guidance, regulations, transparency) increase the possibility of fostering knowledge construction: motivation, guidance, regulation, and transparency. One of the study's implications is to apply the four pillars to improve online discussion in classes and other researchers are encouraged to expand the study of CMV as a context for knowledge construction and to examine the four pillars' application in other contexts. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]