ABSTRACT
Text understanding is usually hard for computers and easy for people, so we tend to forget about the times when it’s hard for people, too. But even smart, knowledge-based people, and not just dumb computers, can find text understanding extremely difficult. We all know this from our experiences with writing that presents complex ideas—advanced technical papers, for example—and writing that’s just plain bad—incomprehensible instructions for assembling a Christmas toy, textbooks that present ideas sloppily, government tax-return guides that try hard to be clear but never quite succeed. 1 So it’s no shame if a natural language understanding program, like a human, has to occasionally capitulate and say, in effect, that it cannot fully understand some difficult piece of text.
