Fig. 1

From: Extract Implicit Semantic Friends and Their Influences from Bipartite Network for Social Recommendation

A simple example of a social trust network where sparsity is a great concern but not fully considered in real recommendation. b An example of sharing partial preferences among friends where Tom is a friend of Mike and Angel, but the common preference aspects are distinct (football between Tom and Mike while traveling between Tom and Angel). c An example of a social inconsistency problem, where u1 and u2 are context-level inconsistent neighbors, u2 and u3 exist in relation-level inconsistency