1. A method for correlating input data comprising correlation data, wherein the correlation data describes at least one hierarchy comprising a first hierarchy, wherein each hierarchy of the at least one hierarchy comprises at least two nodes, wherein the nodes of each hierarchy of the at least one hierarchy each comprise a value and are each designated as an ontology end point consisting of a unique positive integer, said method being implemented by execution of computer readable program code on a processor of a computer system, said method comprising: for each hierarchy of the at least one hierarchy, computing and storing in a first computer-readable storage medium of the computer system: a unique relationship number RN as a function of X and Y for each pair of parent-child nodes of said each hierarchy of the at least one hierarchy, wherein X and Y respectively denote the ontology end point of the parent node and the child node of said each pair of parent-child nodes; and computing at least one measure of correlation between the first hierarchy and other information comprising a second hierarchy of the at least one hierarchy or publication information extracted from a transient data feed, said computing the at least one measure of correlation being in response to a query that identifies the at least one measure of correlation to be computed, wherein said computing the at least one measure of correlation comprises retrieving and utilizing each stored relationship number of the first hierarchy; and outputting information relating to the computed at least one measure of correlation.