The document discusses using social software effectively for education. It describes three levels of granularity for social learning: groups, networks, and collectives. Groups have clear membership and rules, networks are fluid connections, and collectives harness the wisdom of crowds through aggregation. Formal education can benefit from all three levels by designing activities that leverage their unique affordances and interactions to enhance learning. Choosing the right tools for each level and developing strategies to promote contribution and literacy are keys to success.