Uncertainty in planning: characterisation, evaluation, and feedback

Uncertainty is a double-edged sword for the planner. Without it, society's need for strategic planning would be much reduced, but its existence is often at the root of much of the criticism which public perceptions of the planning profession induce. In this paper it is argued that not only is the need to take proper account of uncertainty greater than ever before, but so too are the opportunities to do so in practice. Three aspects of the uncertainty question are analysed. How should uncertainty be characterised within the planning process? What influence should the presence of uncertainty have on evaluation procedures? How should plan design respond to the presence of uncertainty? It is concluded that increasingly the required formal techniques and computational capacity are available: planners must be sure to use them to good effect.