The organization of sequences is one of the central forms of organization that gives shape and coherence to stretches of talk and the series of turns of which stretches of talk are composed. The focus of this organization is not, in general, convergence on some topic being talked about, but the contingent development of courses of action. The coherence which is involved is that which relates the action or actions which get enacted in or by an utterance to the ones which have preceded and the ones which may follow. The very root of the word “interaction” underscores the centrality of action to the commerce between people dealing with each other, and this aspect of their conduct is a central preoccupation informing what people do in the turns in which they speak, and informing as well what they are heard to be doing.

We have focused on what is very likely the basic unit of sequence organization – the adjacency pair. There are other types of sequence in conversation, but a very broad range of the sequences we find organized as systematic expansions of adjacency pairs. And at least some sequences which may not be based on adjacency pairs nonetheless have some of their parts constituted by these sequence-constructional units.

We started by considering the basic, minimal form of the adjacency pair and its constitutive features – two turns, by different speakers, adjacently positioned, one recognizably a first pair part (FPP, or F), the other recognizably a second pair part (SPP, or S), with the two drawn from the same pair (or sequence) type.