Patent ID: 7587407

Claim:
A computer-implemented method executable by a computer accessing a tangible computer-readable medium, the method establishing a data structure identifying the co-occurrence of entities in a plurality of electronic documents comprising: for at least some of the documents, classifying annotations in a document that correspond to the entities into annotation vectors for the document; for at least some of the documents, inverting the annotation vectors into a table of unique annotations and a list of the unique annotations for the document; defining an inner set of entities of primary interest comprising inner entities; setting an outer set of entities of interest comprising outer entities to determine whether a relationship exists between one of the outer entities and one of the inner entities; retrieving the lists of the unique annotations for each of the documents; determining pairs of inner entities and outer entities which occur within a proximity boundary; in response to a pair occuring within the proximity boundary, comparing the unique annotations for the corresponding locations of the inner entity and the outer entity of the pair; producing a table of all unique pairs which occurred and the number of times the pairs occurred; and deriving a sparse matrix from the table, wherein the inverting comprises recording location, span, and unique identifiers for each of the unique annotations, wherein in response to a particular annotation having occurred more than once in the document, structuring the locations of the annotations as a list of annotations, sorted by the order in which the individual annotations occurred in the document, wherein the defining comprises setting the inner set as the set of all entities, wherein the setting comprises making the outer set a set of all entities.