This study investigates student interactions in a blog-based learning community in a university course. In addition, this study explores the dynamics of group interactions in individual blog-based environments compared with collaborative "wiki"-based educational activities. A learning community of 56 graduate students wrote individual blogs and weekly group summaries using a "wiki" environment. The posts were analyzed by identifying a post content type and explicit feedback promotions, and by counting the number of the blogger's own comments and the number of others' comments per post, received from peers studying in the same versus the other offline group. The results show that choosing the appropriate type of post content (i.e., sharing experiences rather than providing information, explicitly calling for feedback, and providing the blogger's own comments) augments peer interaction in a blog environment, thus explaining 51.4% of variance in peer comments. Group interactions through comments in individual blogs, without the possibility of changing one another's content, seem to be non-intrusive and prompt interactions with offline as well as with online peers. In contrast, actual editing of texts through multi-authored collaborative "wikis" remained affected by student offline former acquaintance. The results are discussed in terms of social interactions and pedagogical beliefs.