Relevance and definition.

The study examined whether the use of superordinate terms in children's definitions was predicted by relevance theory. Two hundred and six children aged five to ten years gave definitions for 16 basic-level words and four superordinate words from natural kind and artefact semantic domains. Superordinate terms were used more frequently when they supported more inferences. This was evidenced by their more frequent use in natural kind than in artefact domains, and more frequent use when the superordinate was itself defined by a semantically complex expression. When used, superordinates also usually occurred at the beginning of the definitional expression. It is argued that these findings reflect the speaker's intention to achieve optimal relevance, that is, to achieve maximum contextual effects with the least processing effort.