Gauthier, RobertCostello, Mary JeanWallace, James2021-12-072021-12-072022-04https://doi.org/10.1145/3491102.3502076http://hdl.handle.net/10012/17742© {Robert P. Gauthier, Mary Jean Costello, and James R. Wallace | ACM} {2022}. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in { In CHI Conference on Human Factors in Computing Systems }, https://doi.org/10.1145/3491102.3502076.Recovery from addiction is a journey that requires a lifetime of support from a strong network of peers. Many people seek out this support through online communities, like those on Reddit. However, as these communities developed outside of existing aid groups and medical practice, it is unclear how they enable recovery. Their scale also limits researchers' ability to engage through traditional qualitative research methods. To study these groups, we performed a topic-guided thematic analysis that used machine-generated topic models to purposively sample from two recovery subreddits: r/stopdrinking and r/OpiatesRecovery. We show that these communities provide access to an experienced and accessible support group whose discussions include consequences, reflections, and celebrations, but that also play a distinct metacommunicative role in supporting formal treatment. We discuss how these communities can act as knowledge sources to improve in-person recovery support and medical practice, and how computational techniques can enable HCI researchers to study communities at scale.enRedditmachine learningthematic analysisaddictiononline communitiesArticle