The Implicit Content of Sluicing

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

In planning their linguistic expressions, speakers and writers are often able to leave out informationally redundant grammatical material, such as when the verb "call" is omitted in "Fred called, but Sheila didn't". This process, known as ellipsis, is widespread across the languages of the world, and is particularly common in informal language and dialogue. Among the many varieties of ellipsis is sluicing, where what is omitted is not a verb but an entire sentence. For example, a speaker may choose to leave out the understood sentence "he called" after "why" in a sentence like: "He called, but I don't know why". Ellipsis poses challenging scientific and engineering problems. Research over the past 50 or 60 years has demonstrated that the principles permitting ellipsis involve many different kinds of information (grammatical structure, the dynamics of the discourse context, and real-world knowledge), but the precise character of these principles and their interaction is still an open question. Progress has been hampered by the lack of a crucial resource type: databases of felicitous uses of ellipsis that are large enough to validate theories against, and rich enough to form the basis for machine learning. The first goal of this project is to build such a database for sluicing and to make it freely available to language scientists and engineers. This resource will be a large, curated corpus of naturally occurring ellipses, annotated at a level of sophistication that will allow a range of analytic questions to be probed quantitatively. As the curation and annotation proceed, patterns that emerge from the data will be used to investigate the interplay between grammar and context that makes ellipsis possible. Since ellipsis is a pervasive feature of human language, to better understand how it works is to better understand the nature of human linguistic behavior itself. This project should also stimulate technological innovation in an area of urgent need: in designing more sophisticated systems for interfacing with natural human conversation, which is replete with ellipses of every kind.