Indicates a periodic structure in the distribution of between-turn silences in two-party conversation, a finding that is inconsistent with current stochastic or signaling models, which view social interaction as an exchange of stimuli and responses. Finds that social interaction is fundamentally a collaborative activity. (JD)

Early speech-act theorists studied isolated speech acts, often in terms of single sentences invented by the investigator, an approach that had obvious limitations. It is now known that speech acts ought to be investigated by looking at utterances in their full interactional context. A hierarchical model of the structure of conversation that is…