ABSTRACT
This chapter focuses on the principles and practice of importance weighting in decisions related to the selection of an aquifer restoration strategy for meeting a given need. It presents techniques for evaluation of alternatives relative to a series of decision factors. The chapter provides a conceptual framework for trade-off analysis and examples of both informal and structured approaches for importance weighting. It briefly addresses the ranking/rating/scaling of alternatives, followed by information on the development of a decision matrix. Ranking techniques for importance weighting basically involve the rank ordering of decision factors in their relative order of importance. The Nominal Group Process technique, an interactive group technique, was derived from social-psychological studies of decision conferences, management science studies of aggregating group judgments, and social work studies of problems surrounding citizen participation in program planning. Rating techniques for importance weighting basically involve the assignment of importance numbers to a series of decision factors, and their subsequent normalization via a mathematical procedure.
