A component-based generic agent architecture for multi-attribute (integrative) negotiation is introduced and its application is described in a prototype system for negotiation about cars, developed in co-operation with, among others, Dutch Telecom KPN. The approach can be characterised as co-operative one-toone multi-criteria negotiation in which the privacy of both parties is protected as much as possible. 1

This paper presents a model for integrative, one-to-one negotiation in which the values across multiple attributes are negotiated simultaneously. We model a mechanism in which agents are able to use any amount of incomplete preference information revealed by the negotiation partner in order to improve the efficiency of the reached agreements. Moreover, we show that the outcome of such a negotiation can be further improved by incorporating a "guessing" heuristic, by which an agent uses the history of the opponent's bids to predict his preferences. Experimental evaluation shows that the combination of these two strategies leads to agreement points close to or on the Pareto-efficient frontier. The main original contribution of this paper is that it shows that it is possible for parties in a cooperative negotiation to reveal only a limited amount of preference information to each other, but still obtain significant joint gains in the outcome.

CWI is a founding member of ERCIM, the European Research Consortium for Informatics and Mathematics. CWI's research has a theme-oriented structure and is grouped into four clusters. Listed below are the names of the clusters and in parentheses their acronyms.

This paper discusses the strengths and weaknesses of non-monotonic-offers in alternating-offer bargaining protocol. It is commonly assumed that bargainers submit monotonic offers over time, which correspond to their belief revisions. However, through formal analysis and simulations, we are able to show that nonmonotonic -offers protocols can generate higher average surplus and lower breakdown rate compared to monotonic-offers protocols.

Introduction Electronic markets are becoming increasingly transparent with low search cost, strong price competition, and low margins. Automated negotiation enables a business to go beyond price competition. Through the use of autonomous agents, which negotiate on behalf of their owners, a business can obtain flexibility in prices and goods, distinguish between groups of buyers based on their preferences, and even personalize complex goods according to the demands of individual buyers without significantly increasing transaction costs. We focus here on one-to-many bargaining, where a seller agent negotiates, on behave of a seller, with many buyer agents individually in a bilateral fashion. In many cases, auctions can be used to effectively organize one-to-many bargaining. For various situations, however, auctions may not be the preferred protocol for bargainers. In situations of, for example, flexible or virtually unlimited supply, multiple issues, and/or continuous sale the appropri