Hierarchical tag-graph search for spontaneous speech understanding in spoken dialog systems
Bor-Shen Lin, Berlin Chen, Hsin‐Min Wang, Lin-shan Lee · 1998
It has been relatively difficult to develop natural language parsers for spoken dialog systems, not only because of the possible recognition errors, pauses, hesitations, out-ofvocabulary words, and the grammatically incorrect sentence structures, but because of the great efforts required to develop a general enough grammar with satisfactory coverage and flexibility to handle different applications. In this paper, a new hierarchical graph-based search scheme with layered structure is presented, which is shown to provide more robust and flexible spontaneous speech understanding for spoken dialog systems. 1.INTRODUCTION Traditionally, natural language understanding is integrated with the speech recognizer with a N-best interface in spoken dialog systems [1][2], that is, the recognizer sequentially generates its best N sentence hypotheses until any one is accepted by the natural language understanding part. However, for spontaneous speech with fragments, disfluencies, OOV words, and ill-...