Information Seeking Spoken Dialogue Systems- Part I: Semantics and Pragmatics

In this paper, the semantic and pragmatic modules of a spoken dialogue system development platform are presented and evaluated. The main goal of this research is to create spoken dialogue system modules that are portable across applications domains and interaction modalities. We propose a hierarchical semantic representation that encodes all information supplied by the user over multiple dialogue turns and can efficiently represent and be used to argue with ambiguous or conflicting information. Implicit in this semantic representation is a pragmatic module, consisting of context tracking, pragmatic analysis and pragmatic scoring sub-modules, which computes pragmatic confidence scores for all system beliefs. These pragmatic scores are obtained by combining semantic and pragmatic evidence from the various sub-modules (taking into account the modality of input) and are used to rank-order attribute-value pairs in the semantic representation, as well as identifying and resolving ambiguities. These modules were implemented and evaluated within a travel reservation dialogue system under the auspices of the DARPA Communicator project, as well as for a movie information application. Formal evaluation of the semantic and pragmatic modules has shown that by incorporating pragmatic analysis and scoring, the quality of the system improves for over 20% of the dialogue fragments examined. EDICS Category: 3-DIAL 3-MODA 3-INTF Egbert Ammicht is with Bell Labs, Lucent Technologies, Whippany, NJ 07981, USA; email: [email protected]; tel: +1-973-386-7139. Eric Fosler-Lussier is with the Dept. of Computer Science and Engineering, The Ohio State University, Columbus, OH 43210, USA; email: [email protected]; tel: +1-614-292-4890; fax: +1-614-292-2911. Alexandros Potamianos is with the Dept. of Electronics & Computer Engineering, Technical Univ. of Crete, Chania 73100, Greece; email: [email protected]; tel:+30-28210-37221; fax:+30-28210-37542. Some of this work was performed while Alexandros Potamianos and Eric Fosler-Lussier were with Bell Labs, Lucent Technologies, Murray Hill, NJ 07974, USA. TRANS. ON MULTIMEDIA, VOL.X, NO.XX 2 Information Seeking Spoken Dialogue Systems – Part I: Semantics and Pragmatics