Empirical Studies inComputer-MediatedInterest-Based Negotiations

Sohan D’souzaMSc IT, 2009British University in Dubai

Study Focus

Bilateral repeated negotiation under incomplete information

Strategic role of goal information Effect of goal revelation on human

negotiation strategy

Consider this …

What if …

Then maybe …

Contributions Design of interest-based protocol for

incomplete goal information, goal inquiry and goal revelation

First study to investigate outcomes and human use of goal revelation in task settings

Comparison of human negotiation strategies between position- and interest-based negotiation

Significance

For Multi-Agent Systems For Decision Support Systems For Cognitive Science For Psychology

Topics in Negotiation

Issues and Outcomes Task Dependency Distributive vs. Integrative Position-based vs. Interest-based Multi-Agent System vs. Human

Related Work Interest-based negotiation specific to

domains (Loewenstein et al., 1989) Pre-negotiation goal framing

(Loewenstein and Brett, 2007) Position-based agent vs. human

negotiations (Lin et al. 2008; Bosse and Jonker, 2005)

Human caution with information privacy (Heiskanen et al., 2001)

Colored Trails - Platform

Multiplayer client-server platform Board of colored tiles Traversal by expending colored chips Icons representing players and goals GUI and decision support tool for

human players

Colored Trails – Relevance

Tiles analogous to different tasks Chips as different resources or

abilities used to complete tasks Traversal route represents candidate

task sequence towards goal Multiple paths to goal possible Information on opponents can be

hidden or revealed

Protocol Design - PBN

Proposer A

Responder B

Responder A

Proposer B

MAKE PROPOSAL

MAKE PROPOSAL

REJECT

ACCEPT

REJECT

ACCEPT

Position-based Negotiation (PBN) Protocol

Turn-based play

Rejections switch roles

Protocol Design - IBN

Proposer A

MAKE PROPOSAL

REJECT

ACCEPT

REJECT

ASK FOR GOAL

MAKE PROPOSAL

ASK FOR GOAL

Responder B

Responder A

Proposer B

ACCEPT

REVEAL GOAL

Interest-based Negotiation (IBN) Protocol

Can ask for goal only in response to offer

Can reveal goal only when asked

Game Setup

5x5 tile layout, 7 chips assigned At most one player can independently

reach their goal Chip assignment allows for at least

one player to get to goal by trading Only one shortest path possible Scoring function favors resource

conservation and gives partial credit

Experimental Setup

Masks and GUI changes to control information visibility and actions

Single game settings pool shared across both negotiation protocols

4 communication minutes per game, else default to existing assignment

Each player anonymously plays each other player once, in both initial roles

Results - Performance

Average benefit for players in IBN/PBN conditions for different number of goal revelations (significant difference in bold)

Average benefit for players in IBN/PBN conditions for different player dependencies (significant difference in bold)

Results - Agreement

Pair-wise agreement ratio

Agreement frequencies by task dependency

Results – Goal Revelation

  Independent Dependent Both

Goal Revelations 16 (27%) 43 (73%) 59 (100%)

Revelation/Solicitation 16/26 (62%) 43/50 (86%) 59/76 (78%)

Goal revelation distribution and frequency

Discussion

Adapted platform robust and flexible Humans show unexpected trust in

volunteering goals when asked Self-sacrifice observed on the part of

independent players Possible cautionary generosity on the

part of dependent players

Future Work

Comparing to games with initially complete information

Allowing players to reveal goals without being asked

Allowing more than one shortest path Removing anonymity and having

repeated games between players Building classifiers using the data

Conclusions Asked, humans generally reveal goals Both altruistic and satisficing

outcomes observed in IBN Agreement likelihood and social

benefit higher in IBN Strategic benefit of goal information

varies with task dependency Precedent for future work on goal

revelation in mediated IBN scenarios