Multi-phase negotiation for single-item bidding

This article presents a multi-phase bidding model that is primarily for reverse bidding (1:N) and can also be used later for bilateral bidding (1:1). This multi-phase approach excels by competing for the lowest price and relativizes a subtle “lose-win” relationship of its own for the reverse auction through a second phase of negotiation. The latter is limited to a bilateral relationship and is applied, if necessary, between the purchaser and the second or third best offer of the reverse auction. Experiments were conducted with stationary or adaptive negotiation agents using learning techniques to conduct negotiation policy, using a genetic algorithm to characterize the opponent´s preferences and configure the generation of interesting offers. The results showed the influence that an aggressive bidder has on the process as a whole and also what can be done to minimize this effect.