AN ACTION REPRESENTATION FORMALISM TO INTERPRET NATURAL-LANGUAGE INSTRUCTIONS

The focus of this paper is on an action representation formalism that encodes both linguistic and planning knowledge about actions, and that supports the interpretation of complex Natural Language instructions and, in particular, of instructions containing Purpose Clauses. The re presentation uses linguistically motivated primitives, derived from Ja ckendoff's work on Conceptual Semantics, and is embedded in the descri ption logic based system CLASSIC. I first motivate the characteristics of the formalism as needed to understand Natural Language instruction s. I then describe the formalism itself, and I argue that the integrat ion of a linguistically motivated lexical semantics formalism and of a description logic based system is beneficial to both. Finally, I show how the formalism is exploited by the algorithm that interprets Purpo se Clauses. The output of the algorithm is used in the Animation from NL project, that has as its goal the automatic creation of animated ta sk simulations.