Whereas forecasting is the process of predicting the future based on current trend analysis, backcasting approaches the challenge of discussing the future from the opposite direction. Backcasting then is:

a method in which the future desired conditions are envisioned and steps are then defined to attain those conditions, rather than taking steps that are merely a continuation of present methods extrapolated into the future

Typically, several alternative scenarios are examined -- usually representing different normative (or desirable) states. The question is then asked, if we want to arrive at Scenario A, what trends would need to change to get us there. Usually, quantitative analysis provides a feasibility or plausibility assessment. For example, if Scenario A was future in which CO₂ emissions were stabilized at Xppm and Scenario B was CO₂ stabilization at Yppm -- quantitative analysis could help assess which one was more plausible under any given set of assumptions. This would be backcasting.

References

See also

• Global Scenario Group

External links

• Tellus Institute - environmental research group that uses backcasting to develop strategies for sustainability
• Backcasting Presentation from IA Summit 2007 - backcasting as a technique in Information Architecture