Method for learning local syntactic relationships for use in example-based information-extraction-pattern learning

摘要

A method is provided for learning local syntactic relationships for use in an example-based information-extraction-pattern learning element of an automated information extraction system. The example-based learning element learns information extraction patterns from user-provided examples of texts paired with events the texts contain; these patterns can then be used by the information extraction system to recognize similar events in subsequent texts. The learning element learns patterns by analyzing each example text/event pair to determine paths of local syntactic relationships between constituents in the text that indicate the event. The learning element employs an incomplete dictionary of local syntactic relationships for this analysis. The present invention learns new local syntactic relationships for text/event pairs that cannot be analyzed using the learning element's initial, incomplete dictionary of relationships. These new relationships are added to the dictionary, and allow the learning element to learn patterns from example text/event pairs that cannot be analyzed using only the initial dictionary.