Anaphora Resolution using Extended Centen’ng Algorithm in a Multi-modal Dialogue System

Anaphora in multi-modal dialogues have different aspects compared to the anaphora in language-only dialogues. They often refer to the items signified by a gesture or by visual means. In this paper, we define two kinds of anaphora: screen anaphora and referring anaphora, and propose two general methods to resolve these anaphora. One is a simple mapping algorithm that can find items refetxed with/without pointing gestures on a screen. The other is the centering algorithm with a dual cache model, which Walker's centering algorithm is extended to for a multi-modal dialogue system. The extended algorithm is appropriate to resolve various anaphora in a multi-modal dialogue .because it keeps utterances, visual information and screen switching,.tim.e. In the experiments, the system. Correctly resolved 384 anaphora out of 402 anaphom in 40 dialogues (0..54 anaphom per utterance) showing 95.5% correctness.