Combining statistical and syntactical systems for spoken language understanding with graphical models
Stefan Schwärzler, Jürgen T. Geiger, Joachim Schenk, Marc Al-Hames, Benedikt Hörnler, Günther Ruske, Gerhard Rigoll · 2008
There are two basic approaches for semantic processing in spoken language understanding: a rule based approach and a statistic approach. In this paper we combine both of them in a novel way by using statistical and syntactical dynamic bayesian networks (DBNs) together with Graphical Models (GMs) for spoken language understanding (SLU). GMs merge in a complex, mathematical way probability with graph theory. This results in four different setups which raise in their complexity. Comparing our results to a baseline system we achieve a F1-measure of 93.7 % in word classes and 95.7 % in concepts for our best setup in the ATIS-Task. This outperforms the baseline system relatively by 3.7 % in word classes and by 8.2 % in concepts. The expermiments were performend with the graphical model toolkit (GMTK). Index Terms: natural language understanding, machine learning, graphical models