Today there is widespread agreement that participatory methods are useful if not legally required to understand and effectively address environmental management problems. What participatory methods should be used in which situations and particularly how they should be applied are still insufficiently addressed questions. There is limited understanding about the interconnections between project purpose, participatory methods and their application. Participation methods are often selected on the basis of familiarity or cost considerations. We argue that these trade-offs may compromise the potential outcomes and effectiveness of a project. To address these shortcomings we summarise current knowledge and understanding in the public participation literature. System dynamics projects can benefit substantially from public participation particularly through participative modelling. Much research effort focuses on group model building. For projects where group model building is not a prudent choice, we suggest and discuss alternatives.