7. A computer readable storage medium having embodied thereon a program, the program being executable by a processor to perform a method for assigning scores to a plurality of linked documents, the method comprising: constructing by a processor executing a program a spring network representation according to a connectivity graph of a collection of linked documents and links among the documents, the spring network representation including a plurality of nodes wherein each node corresponds to at least one document, the spring network representation further including an inter-nodal virtual spring connected between each pair of nodes associated with documents having a link between the documents, the inter-nodal virtual spring corresponding to the document link between the corresponding pair of documents; adding a virtual anchor spring to each node in the spring network representation, each virtual anchor spring associated with only one node and not corresponding to a link between any documents; identifying a plurality of nodes as one or more reference nodes and one or more regular nodes, each reference node preselected independently of any other node or relationship of the reference node with any other node; (a) applying a predetermined amount of virtual input displacements on the reference nodes within the spring network representation, the virtual input displacements having constant values and collectively comprising a virtual input displacement vector; (b) determining a virtual strength value for each inter-nodal virtual spring in the spring network representation, each inter-nodal spring virtual strength value derived from the virtual input displacement associated with the pair of nodes connected to a particular inter-nodal virtual spring; (c) calculating one or more virtual inter-nodal forces and a virtual anchor spring force that collectively virtually act on each node in the spring network representation, each inter-nodal force derived from the product of the virtual strength value of the inter-nodal virtual spring and virtual displacement of a particular node, each virtual anchor spring force derived from the product of an anchor spring strength and the virtual displacement of the particular node; (d) calculating a total force on each node in the spring network representation as the sum of all the virtual inter-nodal forces associated with each particular node and the virtual anchor spring force for the particular node, the total force on each node in the spring network representation collectively set as a virtual output displacement vector; (e) comparing the virtual output displacement vector and the virtual input displacement vector for the plurality of nodes; determining that the virtual output displacement vector and the virtual input displacement vector do not converge; (f) adding the virtual output displacement vector and the virtual input displacement vector for the plurality of nodes to derive a new virtual input displacement vector as the sum of the virtual output displacement vector and the virtual input displacement vector, the adding performed based on the non-convergence, a new virtual input displacement vector to be used as a new predetermined amount of virtual input displacement vector; repeating the steps (a)-(f), the repeated steps performed based on substituting the value of the pre-determined amount of virtual input displacement with values of the new virtual input displacement vector, the steps repeated until the virtual output displacement vector and the virtual input displacement vector converge; and assigning scores to documents based on values of the virtual output displacement vector of the nodes that correspond to the documents when the virtual output displacement vector and the virtual input displacement vector converge for each node within the spring network representation.
7. A computer readable storage medium having embodied thereon a program, the program being executable by a processor to perform a method for assigning scores to a plurality of linked documents, the method comprising: constructing by a processor executing a program a spring network representation according to a connectivity graph of a collection of linked documents and links among the documents, the spring network representation including a plurality of nodes wherein each node corresponds to at least one document, the spring network representation further including an inter-nodal virtual spring connected between each pair of nodes associated with documents having a link between the documents, the inter-nodal virtual spring corresponding to the document link between the corresponding pair of documents; adding a virtual anchor spring to each node in the spring network representation, each virtual anchor spring associated with only one node and not corresponding to a link between any documents; identifying a plurality of nodes as one or more reference nodes and one or more regular nodes, each reference node preselected independently of any other node or relationship of the reference node with any other node; (a) applying a predetermined amount of virtual input displacements on the reference nodes within the spring network representation, the virtual input displacements having constant values and collectively comprising a virtual input displacement vector; (b) determining a virtual strength value for each inter-nodal virtual spring in the spring network representation, each inter-nodal spring virtual strength value derived from the virtual input displacement associated with the pair of nodes connected to a particular inter-nodal virtual spring; (c) calculating one or more virtual inter-nodal forces and a virtual anchor spring force that collectively virtually act on each node in the spring network representation, each inter-nodal force derived from the product of the virtual strength value of the inter-nodal virtual spring and virtual displacement of a particular node, each virtual anchor spring force derived from the product of an anchor spring strength and the virtual displacement of the particular node; (d) calculating a total force on each node in the spring network representation as the sum of all the virtual inter-nodal forces associated with each particular node and the virtual anchor spring force for the particular node, the total force on each node in the spring network representation collectively set as a virtual output displacement vector; (e) comparing the virtual output displacement vector and the virtual input displacement vector for the plurality of nodes; determining that the virtual output displacement vector and the virtual input displacement vector do not converge; (f) adding the virtual output displacement vector and the virtual input displacement vector for the plurality of nodes to derive a new virtual input displacement vector as the sum of the virtual output displacement vector and the virtual input displacement vector, the adding performed based on the non-convergence, a new virtual input displacement vector to be used as a new predetermined amount of virtual input displacement vector; repeating the steps (a)-(f), the repeated steps performed based on substituting the value of the pre-determined amount of virtual input displacement with values of the new virtual input displacement vector, the steps repeated until the virtual output displacement vector and the virtual input displacement vector converge; and assigning scores to documents based on values of the virtual output displacement vector of the nodes that correspond to the documents when the virtual output displacement vector and the virtual input displacement vector converge for each node within the spring network representation. 8. The method of claim 7 , wherein the convergence is determined by an error function.