Final answer:
The Delphi technique is the formalized method used to transform group opinions into quantitative measures for decision-making, involving a series of expert questionnaires with feedback iterations.
Step-by-step explanation:
A formalized method for transforming the opinions of a group of individuals into quantitative measures that can be aggregated for use in decision-making is referred to as the Delphi technique. This technique involves a series of questionnaires sent to a panel of experts, with feedback provided between rounds to allow for refinements and adjustments to their responses. The objective of this process is to achieve a convergence of opinion on a specific issue. The Delphi technique is particularly valuable in situations where individual judgments must be combined to address complex problems that do not lend themselves to precise analytical techniques.
In contrast, cost-benefit analysis is a decision-making process that involves comparing what one will sacrifice and what one will gain. It is a systematic approach to estimating the strengths and weaknesses of alternatives used to determine options that provide the best approach to achieving benefits while preserving savings. On the other hand, the Program Evaluation and Review Technique (PERT analysis) and sensitivity analysis are more quantitative and project management tools used to plan and control large projects, and to understand how different variables impact a particular outcome, respectively. Thus, the Delphi technique is the answer that fits the description provided in the question.