Using Verb Semantic Role Information to Extend Partial Parses via a Co-reference Mechanism

We describe a technique for the robust interpretation of newswire texts which uses semantic role information about verb complements together with a general co-reference mechanism to extend the constituent structure analysis produced by a partial parser. This technique has the advantage that failure to nd a spanning parse of an entire sentence does not necessarily preclude correct semantic interpretation of, for example, key subject-verb-object relations. An information extraction system employing this technique has been evaluated in the Sixth Message Understanding Conference (MUC-6), and while the scoring protocols in that exercise do not allow a direct assessment of the technique, we can use them to obtain indirect performance measures which give some indication of how much the technique is contributing to overall system performance.