A multi-leveled negotiation framework

In this paper, we present a multi-leveled negotiation framework in which the negotiation process is performed at two levels. The upper level deals with the formation of high level goals and objectives for the agent, and the decision about whether or not to negotiate with other agents to achieve particular goals or bring about particular objectives. The negotiation at this upper level determines the rough scope of the commitment (i.e. the time and the quality characteristics) and the cost of the commitment. The lower level deals with feasibility and implementation operations, such as the detailed analysis of candidate tasks and actions and the formation of the detailed temporal and resource-specific commitments among agents. The negotiation at this lower level involves the refinement of the rough commitments proposed at the upper level. The experimental work shows this two-leveled negotiation framework enables the agent to handle complicated negotiation issues and uncertainties in a more efficient way. 1. NEGOTIATION AT DIFFERENT LEVELS Usually negotiation is structured as a single level process from the proposal to the final commitment, all related issues such as finishing time, achieved quality and offered price are determined in this process. This negotiation can require a complicated reasoning process when the agent has multiple tasks where the tasks may be achieved in different ways and include a sequence of activities, some of which may require external or internal resources. Additionally, uncertainty in task execution may further complicate the negotiation process as behavior deviates from the expected. The This material is based upon work supported by the National Science Foundation under Grant No.IIS-9812755 and the Air Force Research Laboratory/IFTD and the Defense Advanced Research Projects Agency under Contract F30602-99-2-0525. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright annotation thereon. Disclaimer: The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Defense Advanced Research Projects Agency, Air Force Research Laboratory/IFTD, National Science Foundation, or the U.S. Government. deviation can cause re-negotiation over commitments or the adjustment of local activities so as to still meet the commitments. This paper explores an alternative approach to negotiation in which the negotiation process is performed at different abstraction levels to reduce the complexity of the search. The upper level deals with the formation of high level goals and objectives for the agent, and the decision about whether or not to negotiate with other agents to achieve particular goals or bring about particular objectives. The negotiation at this upper level determines the rough scope of the commitment (i.e. the time and the quality characteristics) and the cost of the commitment. The lower level deals with feasibility and implementation operations, such as the detailed analysis of candidate tasks and actions and the formation of the detailed temporal and resource-specific commitments among agents. The negotiation at this lower level also involves the refinement of the rough commitments proposed at the upper level. Let’s look at an example to make these issues concrete. Agent is Adam’s personal assistant agent. Agent is deigned to carry out multiple tasks corresponding to Adam’s multiple goals in his life. Adam is a professor of Asian culture and language and he also has a family. He is asked by his department chair whether he can deliver a talk about his recent research results at the college. Also, he is planning to attend a conference in his research area. Meanwhile, his wife discusses with him the arrangement for their son’s birthday party. Thus, there are three candidate tasks that appear in the agenda of agent : prepare a talk for Adam’s lecture, plan Adam’s trip to a conference, and organize a birthday party for Adam’s son. These tasks are associated with Adam’s different roles, and contribute to different goals. The contributions of these tasks are not interchangeable. Each task has a deadline request, and also has multiple alternative ways to be performed. Figure 1 shows these three tasks. The higher level view describes the deadline for each task, the abstracted plans for each task, the duration of these plans and how they contribute to different goals. The lower level view describes the detailed plan for each task with the specification of the execution characteristics for each primitive tasks. Figure 2 presents the detailed plan for task prepare talk. Agent needs to make decisions about which tasks should be performed, and when and how to perform them. The possible issues that agent can negotiate about include: 1. Negotiation with the secretary agent about when the talk should be delivered, which affects the deadline of the task prepare talk. 2. Negotiation with a translator agent about the task translate material, which includes when this task can be performed and how much it costs. 3. Negotiation with a travel agent about the task book ticket, which includes when this task can be performed and how