Le dialogue homme- machine en langue naturelle : un défi ?

The implementation of a natural language manmachine dialogue in a data base or knowledge base query system is a difficult task. We present hereafter three different approaches to this problem : dialog modeling, exemplified through a linguistic scheme and several computational implementations ; the cooperation principles in a dialog and their associated algorithms ; and, lastly, the artificial intelligence approach based on speech acts theory and the techniques for generating and recognizing plans. We conclude by assessing the possible use of current speech processing techniques and by listing still unsolved problems.