Implementation of generic positive-negative tracker in extensible dialog system

Dialog state tracking is one of the most challenging tasks in the implementation of statistical Dialog Management (DM) systems. In development of a Korean dialog system, we implemented a generic tracking approach that can be used to extend a given initial set of system-output types. Our approach uses two methods: confidence estimation for error modeling, and dialog abstraction for dialog state tracking. We adopted a phoneme-sequence matching algorithm to estimate confidence for erroneous Korean user input. We also adopted a positive-negative model to abstract and generalize the effect of given user input and corresponding system output on dialog-state updating. Experiment result implies that our model can be used for dialog tracking without significant loss of performance. We implemented dialog system to verify that our approach is feasible in a practical Korean dialog system that can be adopted for other languages.