While the choice of an appropriate method is important in determining the success of a participation process it is also true that there are many other factors that are important. The skills of the staff involved, the history of conflict and the clarity of purpose can be just as important, if not more, as the choice of method. For these reasons it is important not to become method-led but to view methods as tools for achieving your purpose.
Involve and Shared Practice's online Guide to Evaluating Participation
provides a helpful overview of some of the different factors that should be taken into account when determining the succcess of a public participation project.