1. A system for conducting a search of a plurality of databases, said system comprising: a processor programmed to: establish a network including a plurality of nodes corresponding to databases and one or more specified links connecting each of the plurality of nodes to another one of the plurality of nodes, wherein each of the one or more specified links includes a topic and indicates an explicit relationship between a pair of nodes of the plurality of nodes, the explicit relationship specified by a network member; receive historical data for previous searches of the network performed by network members, the historical data including a record of an observed relationship between a first node of the plurality of nodes and a second node of the plurality of nodes on a topic, the observed relationship observed from behavior of a search-initiator network member corresponding to the first node and being representative of relevance of the second node to the search-initiator network member on the topic; establish an inferential link between a first inferential node and a second inferential node based on the historical data, the first inferential node corresponding to the first node and the second inferential node corresponding to the second node, the inferential link indicating the observed relationship between the first node and the second node and including the topic of the record and a weight; receive a search topic from a searching network member; and search the network for a node of the plurality of nodes relevant to the search topic, wherein search results and/or search order of the network are based at least in part on the weight of the inferential link.