This paper introduces a stochastic interpretation process for composing semantic structures. This process, dedicated to spoken language interpretation, allows to derive semantic frame structures directly from word and basic concept sequences representing the users' utterances. First a two-step rule-based process has been used to provide a reference semantic frame annotation of the speech training data. Then, through a decoding stage, dynamic Bayesian networks are used to hypothesize frames with confidence scores from test data. The semantic frames used in this work have been derived from the Berkeley FrameNet paradigm. Experiments are reported on the Media corpus. Media is a French dialog corpus recorded using a Wizard of Oz system simulating a telephone server for tourist information and hotel booking. For all the data the manual transcriptions and annotations at the word and concept levels are available. In order to evaluate the robustness of the proposed approach tests are performed under 3 different conditions raising in difficulty wrt the errors in the word and concept sequence inputs: (i) according to whether they are manually transcribed and annotated, (ii) manually transcribed and enriched with concepts provided by an automatic annotation, (iii) fully automatically transcribed and annotated. From the experiment results it appears that the proposed probabilistic framework is able to carry out semantic frame annotation with a good reliability, comparable to a semi-manual rule-based approach.
Bibliographic reference. Meurs, Marie-Jean / Lefevre, Fabrice / Mori, Renato De (2008): "A Bayesian approach to semantic composition for spoken language interpretation", In INTERSPEECH-2008, 1161-1164.