The silent negotiation or how to elicit collective information for group MCDA without excessive discussion

Silent negotiation is a procedure designed to help a group of people elicit collective evaluations or weights to be used in Multiple Criteria Decision Analysis (MCDA). Its main feature relies on the fact that the interaction between the participants is based – during specific phases – on what they do (i.e. moving cards), and not on what they say. This explains the apparent paradox of the procedure name. The silent negotiation might be useful in many situations, particularly when a unique collective result is required and no argument seems able to influence the participants' opinion. A good example is the elicitation of weights for public procurement. The article describes in detail the elicitation of collective weights using the Cards elicitation procedure and the necessary changes to adapt it to: (1) the evaluation of alternatives on a given criterion and (2) various MCDA methods. The different ways to customize the procedure – by adapting the variables such as the number of moves allowed by round – are presented and discussed. Tests and real-world cases are briefly described. Finally, the main issues related to the silent negotiation are discussed.