Cognition, 27 (1987) 181-218 3 Saying what you mean in dialogue: A study in conceptual and semantic co-ordination* SIMON GARROD Glasgow University ANTHONY ANDERSON Strathclyde University Abstract This paper explores how conversants co-ordinate their use and interpretation of language in a restricted context. It revolves around the analysis of the spatial descriptions which emerge during the course of 56 dialogues, elicited in the laboratory using a specially designed computer maze game. Two types of analysis are reported. The first is a semantic analysis of the various types of description, which indicates how pairs of speakers develop different language schemes associated with different mental models of the maze configuration. The second analysis concerns how the communicants co-ordi- nate in developing their description schemes. The results from this study would suggest that language processing in dia- logue may be governed by local principles of interaction which have received little attention in the psychological and linguistic literature to date. Introduction In both psychology and linguistics there is a long tradition of treating speakers and listeners as isolated individuals from a processing point of view. Yet, on most occasions when we speak or listen we do so within the broader interac- tional framework of dialogue, where a major goal of both parties is to achieve mutual intelligibility. To communicate effectively, speaker and listener must co-ordinate their respective use and interpretation of the language, within the *This work was supported by a grant from the Economic and Social Research Council of Great Britain. We would also like to acknowledge the help of Jim Mullin in writing the maze game computer program and the helpful suggestions from Phil Johnson-Laird, Tony Sanford and two anonymous referees who commented on an earlier draft of this paper. Requests for reprints should be addressed to Simon Garrod, Department of Psychology, University of Glasgow, Glasgow, United Kingdom. OOlO-0277/87/$11.90 0 1987, Elsevier Science Publishers B.V.