Abstract
One aspect of the phenomenon of coherence in conversational discourse was addressed in the present study: sequentiality of speech acts. Several models of discourse structure have postulated sequencing rules between speech acts in conversations, but these efforts have been hampered by the lack of an efficient empirical method that can characterize a large body of language data. The lag sequential technique is proposed here as a tool that can be used to abstract a “grammar” of speech act contingency from spoken discourse. Derived patterns of discourse between female adults and preschool children confirmed expectations that most discourse is based upon three fundamental speech act pairings: question-answer, statement-reply, and directive-acknowledgment. It was also found that interlocutor differences in status, knowledge, and conversational ability affected the structure of the discourse in predictable ways.