Our argument is that design patterns largely cluster within cells of the Form-From design space. For example, threaded spaces commonly utilize upvotes, threaded networks often use resharing, and flat networks typically require posting on a "wall" rather than a central feed. If you don't like our 2x3 space, there's also a full 62-dimension treatment in the appendix from our inductive process, as well as a set of 11 categories those fall into. They're more useful for fine-grained distinctions.