Summary

This chapter introduced affiliation networks and the tools provided by NetworkX for working with affiliation networks, with special attention to using projections to create co-affiliation networks. Affiliation networks are ubiquitous in network data. Whenever there is a symmetrical relationship that can connect more than two things, there is an underlying affiliation structure. Many single-mode networks are really co-affiliation networks—projections of affiliation networks onto one type of node. Different projections have different interpretations, such as the number of paths or similarities. Choosing an appropriate projection for the data and for the question being asked can reveal important properties of a network that might otherwise be overlooked. Even as you encounter standard single-mode networks in the rest of this book, and in real-world data, it is often...