Preference ElicitationJaesuk AhnWhy it is difficult?z Preference Elicitation: simply ranking a set of objectsAHP (Analytic Hierarchy Process)z (Example) Three alternatives and three criterion. z Using pairwise comparison per each criterionz Normalize each column z Average over the columns11/41/2Alternative 3413Alternative 221/31Alternative 1Alternative 3Alternative 2Alternative 1Criterion 10.1430.1580.111Alternative 30.5710.6320.667Alternative 20.2860.2110.222Alternative 1Alternative 3Alternative 2Alternative 1Criterion 10.137Alternative 30.623Alternative 20.239Alternative 1AverageCriterion 1AHP (Analytic Hierarchy Process)0.0560.2910.653Alternative0.3110.2260.7130.137Alt 30.4280.1010.0550.623Alt 20.2610.6740.2330.239Alt 1FinalC3C2C1Criterionz Solve multi-criteria decision problemsFrom agent’s perspectivez Agents must compute or gather information to determine their values of the items in the auction. z It is difficult. z What can help agents to do this kind of task in the auction?From agent’s perspectivez Agents must compute or gather information to determine their values of the items in the auction. z It is difficult. z What can help agents to do this kind of task in the auction?Good estimation of other agents’ valuations Determining one’s valuation for any given package can be hardHuge number of possible packages to evaluateDetermining one’s valuation for any single item against package biddingAuction designz Which auction types are best to aid agents’valuation problem in the auction with possible package bidding?- Sealed Bid auction? Vickery auction?Problems? Possible Improvement?- Ascending auction (English Auction)?Multi-round Ascending Auctionz (Price Discovery) Chance to refine their bid, therefore, auction design allowed participants to bid effectively without exact information about their valuation.z (Multi-Round Auction) It allows bidders to see the price of all items during the auction. Price-feedback guides bidders to the part of the allocation space on which they are likely to be most competitive, given current bids from other biddersAscending Multi-round combinatorial auctionz Information about Provisional Winner (bidding price) is available (price discovery and package refinement)z Possible coalition among small bidder to avoid threshold problem(auction helps valuation for the small bidder)z Goliath placed bid of $126 on the 4 items. Dave want needs to have only on the these items and can afford to bid up to $25.z Since the end of round, Dave can see price information regarding Goliath. Even though we don’t know what’s next bid from Goliath, auction mechanism can give Dave an idea of minimum bidding amount for him and his partnering to beat Goliath’s current winning bid. (no explicit communication is allowed, though)Staged (multi-round) second-price bid Auctionz Bidder 1: v1 [2, 7]z Bidder 2: v2 = 8z Bidder 3: v3 = [11, 15]z Bidder can refine its lower(LB) and upper(UB) bound on value until 1) LB > ask price or 2) UB < ask price. Bidder bid its LB in the case 1), and leave the auction in the case
View Full Document
Unlocking...