The emergence of the network society has major consequences for the role played by environmental scientists. They are assumed to be able to contribute to new institutional arrangements for collective action. Through deliberations and organised discourses, environmental scientists are expected to help stakeholders to define common ground for action and the sharing of individual problem solving capacities. This paper discusses the consequences of changes in the nature of decision-making in the area of sustainability for the concepts and instruments to be used. As a new learning context the policy laboratory is introduced. Special attention is given to three major types of instruments: gaming, interactive methods and group decision support systems.