Within scientists' research practices for improving agricultural resource management, their use of concepts of sustainability remains problematic. Sustainability means different things to different people, and in different contexts; it is ambiguous (Allen, 1993; MacLeod and Taylor, 1993, 1994) and contentious (Ison and Humphreys, 1993; Penman, 1994). Linguistic and communication analyses are providing convincing evidence that meanings of sustainability emerge from within the human communication environment (Penman, 1994; Shulman, 1996a,b). They argue that this environment is dynamic and, to a large extent, indeterminate. Penman (1994, in press) and Shulman (1996a; also, Shulman and Martinek, in press) have taken this further, suggesting that good scientist-constituent communication practices need to acknowledge that, because the situation is unique for each participant in time and space, differences in meanings will be the norm. Good negotiation uses this indeterminacy to open up possibilities for examining the adequacy of specific sustainability concepts in use.