On Compositionality and Bidirectional Optimization

Abstract

In this paper we revisit the semantic principle of compositionality and argue that compositionality is bidirectional optimization. Underspecification approaches to natural language interpretation generally start with an underspecified or weak meaning, which is strengthened by contextual information. By contrast, the bidirectional optimization approach we advocate proceeds from the strongest possible meaning. This meaning can be changed or weakened by contextual information. Under this approach, the meaning of an utterance is composed in a functional rather than a concatenative way, while contextual sources of information play a major role. Yet, because the context of any utterance is in principle the same for the speaker and the hearer, composition and decomposition procced hand in hand. Hence, bidirectional optimization ultimately guarantees (functional) compositionality.