1. "We are all beginning to realise that one of the most intractable problems is that of defining and locating problems" Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

2. "We use the term 'wicked' in a meaning akin to 'malignant' or 'vicious' or 'tricky' or 'aggressive'... to characterise social problems" Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

3. “ To find the problem is the same thing as finding the solution; the problem can't be defined until the solution has been found” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

4. “ Problem understanding and problem resolution are concomitant to each other” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

5. “ One cannot meaningfully search for information without the orientation of a solution concept; one cannot first understand, then solve” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

6. “ Part of the art of dealing with wicked problems is the art of not knowing too early which type of solution to apply” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

7. “ Every situation is likely to be one-of-a-kind” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

8. “ The aim is not to find the truth, but to improve some characteristics of the world where people live” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber

9. Ten Properties of Wicked Problems 1. There is no definite formulation of a wicked problem. 2. Wicked problems have no stopping rules. 3. Solutions to wicked problems are not true-or-false, but better or worse. 4. There is no immediate and no ultimate test of a solution to a wicked problem. 5. Every solution to a wicked problem is a "one-shot operation"; because there is no opportunity to learn by trial-and-error, every attempt counts significantly. 6. Wicked problems do not have an enumerable (or an exhaustively describable) set of potential solutions, nor is there a well-described set of permissible operations that may be incorporated into the plan. 7. Every wicked problem is essentially unique. 8. Every wicked problem can be considered to be a symptom of another problem. 9. The causes of a wicked problem can be explained in numerous ways. The choice of explanation determines the nature of the problem's resolution. 10. The planner has no right to be wrong. Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973.

10. “ The aim is not to find the truth, but to improve some characteristics of the world where people live” Rittel, H., and M. Webber; "Dilemmas in a General Theory of Planning" pp 155-169, Policy Sciences, Vol. 4, Elsevier Scientific Publishing Company, Inc., Amsterdam, 1973. Horst Rittel and Melvin Webber