Text structures in medical text processing: empirical evidence and a text understanding prototype.

We consider the role of textual structures in medical texts. In particular, we examine the impact the lacking recognition of text phenomena has on the validity of medical knowledge bases fed by a natural language understanding front-end. First, we review the results from an empirical study on a sample of medical texts considering, in various forms of local coherence phenomena (anaphora and textual ellipses). We then discuss the representation bias emerging in the text knowledge base that is likely to occur when these phenomena are not dealt with--mainly the emergence of referentially incoherent and invalid representations. We then turn to a medical text understanding system designed to account for local text coherence.