New Information Distance Measure and Its Application in Question Answering System

In a question answering (QA) system, the fundamental problem is howto measure the distance between a question and an answer, henceranking different answers. We demonstrate that such a distance canbe precisely and mathematically defined. Not only such a definitionis possible, it is actually provably better than any other feasibledefinitions. Not only such an ultimate definition is possible, butalso it can be conveniently and fruitfully applied to construct a QAsystem. We have built such a system ------ QUANTA. Extensive experimentsare conducted to justify the new theory.