A natural logic of speech and speech-like acts with developmental implications

This paper presents the beginnings of a unified categorization system for speech and speech like acts. Hierarchical relationships among categories are taken into account in the context of a model specifying the components of speech and speech-like acts. A metric whereby hierarchically related speech acts can be judged for relative complexity is provided. Since more complex acts are predicted to occur later in development than less complex ones, the framework may provide the basis for predictions about the order of appearance of different speech acts in language acquisition. Preliminary evidence of the sensitivity of the system to differences in levels of language skill is provided from a study comparing language use styles in a group of young normal and older retarded children. Results show that in spite of overall similarities in MLU and syntactico-semantic category usage, the nor mal children used relatively more complex categories of speech acts.