Learning has always been both individual and social, within communities, networks and (particularly in the 20th Century) within institutions. But the balance between structure and agency is shifting, and informal learning is growing exponentially. The Web provides unprecedented opportunities for people to create content, and social software provides opportunities for anyone to create and participate in new types of communities and social networks. This raises two questions: what affordances does this provide for learning, and what frameworks can we use to understand and facilitate these affordances, and benefit from them? In this presentation we will outline a framework based on complexity theory, and test it against some case studies to see whether 'emergent learning' might help us to answer these questions about the new learning ecologies.