Previous research suggests that speakers take addressee needs into account with respect to lexical and conceptual processing (Wilkes-Gibbs & Clark, 1992), but do not necessarily avoid grammatical forms which are difficult for addressees to process (Ferreira & Dell, 2000). Syntactic coordination does occur in dialogue, but these effects may be due to cognitive economy rather than audience design (Branigan, Pickering & Cleland, 2000; Garrod & Anderson, 1987). This paper therefore investigates whether perception of addressee needs affects sentence form, and hence whether syntactic stages of utterance planning are sensitive to such information.
16 pairs of participants played a collaborative 'grid building' game, in which they described geometric shapes to their partner. The stimuli were squares, circles, triangles and stars which were coloured orange, turquoise, yellow or purple and had a stripy, dotty, wavy or chequered pattern. Participants took it in turns to describe picture cards (the Director) and to place them in designated positions on a 3 x 3 grid (the Matcher). The box from which the Matcher selected cards was organised in one of two ways, using a within-subjects design. In one condition, cards sharing the same pattern were grouped together. In the other condition, the cards were organised by colour. A 'helpful' Director should first mention whichever adjective will make it easiest for the Matcher to retrieve the card from the box. If the cards are organised by pattern, the Director should mention pattern before colour (e.g. 'stripy purple square'). If the Matcher's box is organised by colour, descriptions should mention colour before pattern ('purple stripy square').
Participants completed 3 trials per condition, and groups were counterbalanced for the order in which the two blocks were presented. As predicted, Directors produced a significantly higher proportion of 'helpful' descriptions once they knew how the Matcher's array was organised (p<.001). This finding is particularly striking because it suggests that speakers co-operate linguistically even when the communicative consequences are minimal; alternative word orders are equally well understood by the Matcher, and appear to have little effect on time taken to complete the task.
Interestingly, speakers tend to produce helpful descriptions in spite of a strong tendency towards entrained word order. Repeated exposure to one kind of NP does not necessarily prime coordinated but 'unhelpful' descriptions on the following trial, suggesting that (local) frequency-based word order biases can be overridden by a sensitivity to issues of audience design (Clark & Murphy, 1983).
References
Branigan, H. P., Pickering, M. J., & Cleland, A. A. (2000). Syntactic coordination in dialogue. Cognition, 75, B13-B25.
Clark, H. H., & Murphy, G. L. (1983). Audience design in meaning and reference. In J. F. LeNy & W. Kintsch (Eds.), Language and comprehension (pp. 287-299). Amsterdam: North-Holland Publishing Company.
Ferreira, V. S., & Dell, G. S. (2000). Effect of ambiguity and lexical availability on syntactic and lexical production. Cognitive Psychology, 40, 296-340.
Garrod, S., & Anderson, A. (1987). Saying what you mean in dialogue: A study in conceptual and semantic co-ordination. Cognition, 27, 181-218.
Wilkes-Gibbs, D., & Clark, H. H. (1992). Coordinating beliefs in conversation. Journal of Memory and Language, 31, 183-194.