Abstract

In this paper we present a process model of the reasoning underlying arguments of persuasion and its embodiment in a computer program, the PERSUAOER, which gives counsel for the resolution of impasses in collective bargaining. We show how goal trees can be searched to produce arguments involving economic quantities. I ARGUMENTATION STRATEGIES Arguments of persuasion are those used by the participants in cooperative problem solving. While others have worked on argumentation, none so far has worked on persuasive arguments. The work of Flowers, et al. (1982) was concerned with adversary arguments and Spohrer and Riesbeck (1984) have investigated understanding causal relationships among economic quantities based on arguments given in newspaper articles. "Convincing " someone to accept a proposition can be effected by two strategies: 1) showing that the proposition furthers the person's goals, or 2) indicating how refusing the proposition threatens his goals. In labour negotiations, the second strategy is crucial. This paper presents a procedure for constructing threatening arguments during labour mediation. Collective bargaining is the process through which a company and a union arrive at a contract. Argumentation is used to persuade the opposing party to grant concessions, to support one's own demands, and to thwart attempts by the opposition to gain concessions from one's own side. A mediator, called in to help the two sides reach an agreement, tries to convince each party to accept the necessary concessions. The final agreement incorporates the tradeoffs that each party found acceptable. By the time the mediator appears, most secondary issues have been settled. The mediator's job is to convince the parties to accept compromises on the last important issues. Events 1 and 2 below illustrate how a mediator uses threatening arguments to do this. EVENT 1. The company refuses to accept a particular wage settlement. The mediator argues that inefficient plant operation will occur from the resulting employee dissatisfaction