Towards Portable Controlled Natural Languages for Querying Ontologies

Natural Language Interfaces (NLIs) to structured data allow users to interact with a system using written or spoken language to perform tasks that require knowledge of a formal language. Due to natural language complexity and ambiguity, such interfaces usually support a Controlled Natural Language (CNL): a subset of a natural language that includes certain vocabulary and grammar rules that have to be followed. Building vocabulary differs from one system to another, and the way this is performed significantly affects portability : portable CNLs for querying ontologies are those that can be adapted easily to new domains without sacrificing performance. In this paper we describe the approach for dynamically extending the vocabulary supported by such systems, through a dialog with the user.