11. A system comprising: one or more processors; and logic encoded in one or more computer-readable tangible storage media that, when executed by the one or more processors, is operable to: maintain access to a data store of information corresponding to one or more of a plurality of users of a social network environment and one or more of a plurality of concepts and comprising: a plurality of nodes including a set of user nodes that each correspond to a respective user, and a set of concept nodes that each correspond to a respective concept, each node of the sets of nodes being associated with a corresponding structured document; and a plurality of edges that each define a connection between a corresponding pair of nodes from the plurality of nodes; receive a request from a first user corresponding to a first user node for a structured document corresponding to a first concept node; determine a first data set that identifies concept nodes connected by respective edges with one or more user nodes that are each connected by respective edges with both the first user node and the first concept node; determine a second data set that identifies concept nodes connected by respective edges with the first concept node and one or more user nodes that are each connected to the first user node; generate a score for each concept node in the first and second data sets based at least in part on the number of user nodes connected to both the first user node and to the respective concept nodes in the first and second data sets; select one or more concept nodes based on their respective scores as recommended nodes; and transmit to the client device the structured document corresponding to the first concept node, wherein the structured document comprises code executable by a client application to render node names or other identifiers of the recommended nodes for display.
11. A system comprising: one or more processors; and logic encoded in one or more computer-readable tangible storage media that, when executed by the one or more processors, is operable to: maintain access to a data store of information corresponding to one or more of a plurality of users of a social network environment and one or more of a plurality of concepts and comprising: a plurality of nodes including a set of user nodes that each correspond to a respective user, and a set of concept nodes that each correspond to a respective concept, each node of the sets of nodes being associated with a corresponding structured document; and a plurality of edges that each define a connection between a corresponding pair of nodes from the plurality of nodes; receive a request from a first user corresponding to a first user node for a structured document corresponding to a first concept node; determine a first data set that identifies concept nodes connected by respective edges with one or more user nodes that are each connected by respective edges with both the first user node and the first concept node; determine a second data set that identifies concept nodes connected by respective edges with the first concept node and one or more user nodes that are each connected to the first user node; generate a score for each concept node in the first and second data sets based at least in part on the number of user nodes connected to both the first user node and to the respective concept nodes in the first and second data sets; select one or more concept nodes based on their respective scores as recommended nodes; and transmit to the client device the structured document corresponding to the first concept node, wherein the structured document comprises code executable by a client application to render node names or other identifiers of the recommended nodes for display. 18. The system of claim 11 , wherein to generate a score for each concept node, the logic, when executed by the one or more processors, is operable to generate and sum or otherwise combine: one or more coefficient scores between each concept node in the first and second data sets and each of the user nodes connected with the user node corresponding to the first user; one or more coefficient scores between each concept node in the first and second data sets and the node corresponding to the first user; one or more coefficient scores between each concept node in the first and second data sets and the first concept node; or one or more coefficient scores between the node corresponding to the first user and each of the user nodes connected with a concept node in the first or second data sets.