Syntax, Semantics, Pragmatics
By taking a more systematic approach to NLU at these levels, we will be able to create more useful and reliable natural language interfaces.
Issues to resolve: What is the ultimate purpose of language, and how does that influence NLU?
How do phrase-structure grammars work?
How can meaning be interpreted and represented?
How can the syntax and semantics of a system be designed to match the needs of an application?