1. A method for assigning quality scores to documents in a linked database, the method comprising: constructing a nodal network stored in memory, the nodal network comprising: (1) a plurality of nodes that each correspond to a document, wherein one or more of the plurality of nodes are selected as reference nodes that correspond to authoritative documents; (2) unidirectional links connecting nodes that correspond to documents that are hyperlinked together, the unidirectional links originating at nodes that correspond to source documents and terminating at nodes that correspond to destination documents; (3) a reservoir node connected to each of the plurality of nodes by unidirectional links that terminate at the reservoir node; and (4) a quality point pump connected to the reservoir by a unidirectional link that terminates at the quality point pump, the quality point pump connected to each of the reference nodes by unidirectional links that terminate at the reference nodes, the quality point pump configured to circulate quality points through the nodal network; initializing input rank values such that reference node ranks are fixed as the highest rank, a reservoir node rank is fixed as the lowest rank, and each of the plurality of nodes have intermediary and unfixed ranks, wherein quality points flow from nodes having a higher rank to nodes having a lower rank when the nodes are connected by a unidirectional link that terminates at the node having the lower rank; executing instructions using a processor to adjust quality point flow rates for the unidirectional links such that the number of quality points flowing into each node equals the number of quality point flowing out of each node; and computing a quality score for each node based on the number of quality points contained therein.