1. HICSS 36 On the e-Negotiation of Unmatched Logrolling Views Presenter S.C. Cheung scc@cs.ust.hk scc@cs.ust.hk Department of Computer Science Hong Kong University of Science and Technology Co-authors Patrick C.K. Hung Patrick.Hung@csiro.au Dickson K.W. Chiu kwchiu@cse.cuhk.hk

2. 2HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Outline Introduction Motivating Example Offers Making Offers Matching Tradeoff Evaluation Offer Acceptance e-Negotiation Process Model Conclusion & Future Work

3. 3HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Contract Template & Issues Successful negotiation leads to a contract. Standard contract templates exist for common business interactions. A contract template defines the scope of a contract and summarizes the issues to be negotiated. … This lease will start on and last for year(s). The property will be rented with/without* facilities. Tenant is required to pay landlord a monthly rent of. The rent includes/excludes* the management fee. … Example of a lease contract template Issues: DATE, PERIOD, RENT, facilities provision, management fee inclusion, …

4. 4HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Logrolling Negotiation is an iterative process deciding acceptable values of these issues. In each iteration, a party performs tradeoff evaluation across various issues and make offers/counter-offers. In each iteration, a party performs tradeoff evaluation across various issues and make offers/counter-offers. Tradeoff evaluation often requires logrolling – the exchange of loss in some issues for gain in others. Tradeoff evaluation often requires logrolling – the exchange of loss in some issues for gain in others.Problems: What if utility functions that precisely define tradeoff evaluation are unavailable? What if utility functions that precisely define tradeoff evaluation are unavailable? What if each negotiation party adopts a different tradeoff evaluation model, resulting in unmatched logrolling views? What if each negotiation party adopts a different tradeoff evaluation model, resulting in unmatched logrolling views? How to match unmatched logrolling views? How to match unmatched logrolling views? Can privacy of individual logrolling views be protected? Can privacy of individual logrolling views be protected?

5. 5HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Motivating Example - Lease PeriodFacilities Allowance Start Date Basic Rent Period Facilities Facilities Allowance Start Date Basic Rent Landlord Tenant Mgt Fee Allowance Mgt Fee Allowance Logrolling Sets Rent f: { Rent = Basic Rent + Facilities Allowance + Mgt Fee Allowance } Logrolling View of Tenant Logrolling View of Landlord

6. 6HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Logrolling View of Landlord The landlord’s primary concern is to let the flat as early as possible. Provision of facilities is negotiable subjected to a longer lease and some increase in rent. The inclusion of estate management fee is negotiable subjected to some increase in rent. PeriodFacilities Allowance Start Date Basic Rent Landlord Mgt Fee Allowance Rent

7. 7HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Logrolling View of Tenant The tenant’s primary concern is to have a shorter lease, leaving flexibility for potential job relocation. Willing to pay a higher rent if facilities and/or estate management fee are included. Period Facilities Facilities Allowance Start Date Basic Rent Tenant Mgt Fee Allowance Rent

8. 8HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views How to Evaluate Tradeoffs? Landlord Tenant logrolling sets

9. 9HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Exchanging Offers in Unmatched Views Logrolling Sets Offer by means of Aggregated View e-Negotiation Support System (eNSS) Negotiation Party Negotiation Party e-Negotiation Support System (eNSS) Aggregated View Logrolling Sets Offer Matching Table Logrolling Sets Tradeoff evaluation In Logrolling View Tradeoff evaluation In Logrolling View

10. 10HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Construction of Aggregated View Given N logrolling sets L 1, L 2, …, L N Aggregrated View = f(L 1 x L 2 x … x L N ) 3 entries in Logrolling sets f: Rent = Basic Rent + Facilities Allowance + Mgt Fee Allowance An entry in aggregated view  Cartesian Product

11. 11HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Aggregated View due to Landlord Logrolling Sets of Landlord’s Offer Aggregated View

12. 12HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Aggregated View due to Tenant

13. 13HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Offer Matching Table Merging two aggregated views

14. 14HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Tradeoff Evaluation by Tenant Tradeoff evaluation is an iterative process. In each iteration, party picks the most concerned logrolling set which has not yet evaluated. Map entries in the offer matching table to the logrolling set. Period Basic Rent Entries in the original logrolling set supplied by Tenants Minimum difference in each combination of template variables in offer matching table Most concerned logrolling set

15. 15HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Revision of Reservation Prices Revise reservation prices, if applicable. Proceed to further tradeoff evaluation based on an entry, which has or has not been revised. Period Basic Rent Min Difference 1 yr 18K  19K 2K  1K 2 yrs 17K 2K

16. 16HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Further Tradeoff Evaluation Combinations not found in the original logrolling set Combinations not found in counterparty’s offer Possible options Evaluation based on Period = 1 year and Basic Rent = 19K

17. 17HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Tradeoff Evaluation Scenario A scenario of tradeoff evaluation can be represented in a tree. A party evaluates his/her logrolling sets in turn.

18. 18HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Tradeoff Evaluation Scenarios A party may arbitrarily change its evaluation order of logrolling sets. A party evaluates tradeoff and revises its reservation prices based on their individual logrolling views.

19. 19HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Candidate Acceptable Offer Successful negotiation results in a set of acceptable offers Selection of each offer leads to a contract. … The lease will start on June 20, 2002 and last for two years. The property will be rented with facilities. Tenant is required to pay landlord a monthly rent of $20,000. The rent excludes the management fee. …

20. 20HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Candidate Acceptable Offer The first acceptable offer represents Landlord compromises the rent (21K  20K) but enjoys the gain (1M early start date & 2 yrs long lease). Landlord compromises the rent (21K  20K) but enjoys the gain (1M early start date & 2 yrs long lease). Tenants compromises the lease period (1yr  2yrs) but enjoys the gain (comfortable rent). Tenants compromises the lease period (1yr  2yrs) but enjoys the gain (comfortable rent). This is a win-win situation after a logrolling process. This is a win-win situation after a logrolling process.

21. 21HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Negotiation Process select e-Contract template identify logrolling issues define issues and criteria make offers & counter offers validate consistency introduce auxiliary variables & specify relations [all issues have been mapped] [consistent] [inconsistent] creation of e-Contract [reach consensus on all reservation prices] [quit] map issues to variables organize logrolling views

22. 22HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Conclusion We have proposed a pragmatic approach to negotiation under unmatched logrolling views. It does not require the use of utility functions and normative models. It does not require any exchanges of logrolling views between negotiation parties. This facilitates privacy of logrolling views, which represents individual’s tradeoff evaluation model. A prototype is being built based on the approach proposed.

23. 23HICSS36 - sccOn the e-Negotiation of Unmatched Logrolling Views Future Work To investigate multi-lateral negotiations. To support changes of logrolling views during negotiation. To apply the approach to other work [1,2,3,4,5]. 1.S.C. Cheung, Dickson K.W. Chiu and Sven Till, A Data-Driven Methodology to Extending Workflows to E- services over the Internet (HICSS-36), January 2003. 2.Dickson K.W. Chiu, S.C. Cheung and Sven Till, A Three Layer Architecture for E-Contract Enforcement in an E-Service Environment (HICSS-36), January 2003. 3.Dickson K.W. Chiu, Wesley C.W. Chan, Gary K.W. Lam, S.C. Cheung and Franklin T. Luk, An Event Driven Approach to Customer Relationship Management in e-Brokerage Industry (HICSS-36), January 2003. 4.Patrick C.K. Hung, A Primitive Study of Logrolling in e-Negotiation (HICSS-36), January 2003. 5.S.C. Cheung and Dickson K.W. Chiu, A Watermarking Infrastructure for Enterprise Document Management (HICSS-36), January 2003.

24. Questions and Answers scc@cs.ust.hk Patrick.Hung@csiro.au kwchiu@cse.cuhk.hk

25. Meta-model Template Variable Party Negotiation Process Accepted Reservation Price Reservation Price makes 1..* holds 1..* * 2..* involves Issue 1 Contract Auxiliary Variable relates to Variable Accepted Offer maps to Offer e-Contract Conceptual Model e-Negotiation Conceptual Model 1 1..* 1 * * resolves 1..* Task 1 Logrolling Set Logrolling View maps to 1 1