Patent ID: 7624083

Claim:
A comparison engine for generating a ranked list of alternatives, the comparison engine comprising: a tradeoff module, the tradeoff module having at least two tradeoff criteria, the at least two tradeoff criteria having a range of possible values, the tradeoff module being capable of receiving assigned values for the at least two tradeoff criteria, a criteria behavior module, the criteria behavior module being capable of analyzing predetermined attributes for a set of alternatives, where the attributes include values of the tradeoff criteria, the criteria behavior module being further capable of generating a set of scores reflecting desirability of the attributes using at least logic diagrams, a scoring and ranking module, the scoring and ranking module being capable of receiving the assigned values from the tradeoff module and the set of scores from the criteria behavior module and generating a ranked list of alternatives, an authentication module for authenticating a user's identity, wherein the comparison engine is used to facilitate a reverse auction, the reverse auction including a solicitation process facilitated by the comparison engine, and the authentication module is used to authenticate a buyer and at least one seller in the reverse auction.