Homophily of Vocabulary Usage: Beneficial Effects of Vocabulary Similarity on Online Health Communities Participation.

Online health communities provide popular platforms for individuals to exchange psychosocial support and form ties. Although regular active participation (i.e., posting to interact with other members) in online health communities can provide important benefits, sustained active participation remains challenging for these communities. Leveraging previous literature on homophily (i.e., "love of those who are like themselves"), we examined the relationship between vocabulary similarity (i.e., homophily of word usage) of thread posts and members' future interaction in online health communities. We quantitatively measured vocabulary similarity by calculating, in a vector space model, cosine similarity between the original post and the first reply in 20,499 threads. Our findings across five online health communities suggest that vocabulary similarity is a significant predictor of members' future interaction in online health communities. These findings carry practical implications for facilitating and sustaining online community participation through beneficial effects of homophily in the vocabulary of essential peer support.