The seminal work on discourse analysis was carried out in classrooms, and it is from this that an understanding of structure of the exchanges that make up spoken discourse is drawn. Sinclair and Couithaerd (1975) identified three levels of discourse: the exchange, a turn-taking interactional sequence; the move, or contribution of a participant to the exchange in a turn; and the act, identifiable within the move and playing a specific linguistic function such as questioning or …showed first 75 words of 666 total…

…showed last 75 words of 666 total…information - a request to the other speaker to supply missing information about which the speaker for information/ ideas about which the speaker has assumptions and for which the speaker is seeking confirmation. Elicits of confirmation are further classified using varying levels of speaker commitment to the act. This study adopts Basturkmen's classification, which, in systemic linguistic terms, lies in the interpersonal function, and it is discussed in more detail in the section on methodology.