My research interests span a range of issues covering natural language understanding, discourse, knowledge representation, common-sense reasoning and planning. I am particularly interested in the overlap between natural language understanding and reasoning. While most of the NLP field has moved to statistical learning methods as the paradigm for language processing, I believe that deep language understanding can only currently be achieved by significant hand-engineering of semantically-rich formalisms coupled with statistical preferences. For further discussion of this viewpoint, see the state of NLP . For a more general discussion of AI, see my keynote address from the 1998 AAAI National conference here . The TRIPS project is a long-term effort to build generic technology for dialogue systems (both spoken and 'chat' systems), which we have now pursued for over a decade.