This paper reports an experiment which demonstrates the emergence of group-specific sublanguages or 'expert-ese' within groups engaged in a series of task-oriented dialogues. Extending the findings of Garrod and Doherty (1994), it is argued that neither simple appeal to task expertise nor the collaborative establishment of mutual beliefs can adequately account for these results. An alternative proposal, that identifes repair as the critical locus of semantic coordination is sketched.
