Pii: S0010-0277(99)00081-5

There is substantial evidence that speakers co-ordinate their contributions in dialogue. Until now, experimental studies of co-ordination have concentrated on the development of shared strategies for reference. We present an experiment that employed a novel confederate-scripting technique to investigate whether speakers also co-ordinate syntactic structure in dialogue. Pairs of speakers took it in turns to describe pictures to each other. One speaker was a confederate of the experimenter and produced scripted descriptions that systematically varied in syntactic structure. The syntactic structure of the confederate's description affected the syntactic structure of the other speaker's subsequent description. We suggest that these effects are instances of syntactic priming (Bock, 1986), and provide evidence for a shared level of representation in comprehension and production. We describe how these effects might be realized in a processing model of language production, and relate them to previous ®ndings of linguistic co-ordination in dialogue. q 2000 Elsevier Science B.V. All rights reserved.