Team Formation between Heterogeneous Actors

Team Formation between Heterogeneous Actors

Arlette van Wissen

Virginia DignumKobi Gal

Bart Kamphorst

Introduction

How to make decisions in a fast-paced and dynamic domain in which humans and agents interact?

The Problem

2

Introduction


The Problem

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IntroductionTeam Formation

N - TT

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To become part of successful teams, one has to deal with the followingsocial dilemmas:

team formationworking together?allocation of payoff?

team maintenance (intention reconciliation)staying together?

- Identify the tradeoffs between fairness, trust and participant type in dynamic team interactions.

- Derive principles that can be used to construct agents that are able to participate effectively in these settings.

IntroductionTeam Formation

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Introduction


Humans are not completely rational actors. (Kagel & Roth, 1995)

Social factors influence human behavior.

(Loewenstein, 1989, Camerer, 2003)

The Problem

6Fairness

Introduction

How to make decisions in a fast-paced and dynamic domain

in which humans and agents interact?

- changing environment- no predefined teams- non-binding agreements

Trust

The Problem

7

Introduction


Social factors influence cooperation between humans and agents.

(van Wissen et al., 2009)

The Problem

8Actor Type

People behave differently towards agents and other people.

(Blount 1995, Sanfey 2003 )

Related WorkTeam Formation

Existing work on human-agent team formation:

• Uses models that generally do not consider trust or nature.

• Focuses on formal analysis.

• Uses simplifying assumptions.

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Experimental DesignPackage Delivery Domain

Fast paced domain with uncertainty and commitment.

Team Formation: initiators and members.

Social dilemmas:1. working together?2. allocation of payoff?3. staying together?

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Experimental DesignPackage Delivery Domain

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Experimental DesignPackage Delivery Problem in Colored Trails

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Experimental Design

Fairness, Trust

Empirical Methodology

ability to choose team members

&transferable

payoffActor Type

repeated interaction, defection

deception13

Experimental DesignPackage Delivery Problem in CT

- 6 players per game (P)- 3 colors (P/2)

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- 6 players per game (P)- 3 colors (P/2)

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- 6 players per game (P)

- 3 colors (P/2)- 6 large packages

(P)- 12 small packages(2P)

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team formation game with:

- payoff small package = 3

payoff large package with 2 players = 60

payoff large package with 3 player = 180

- imperfect information:players do not have knowledge of all actions and behavior of the players in the game and have partial visibility

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Experimental Design

movie

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The Experiment

2 experiments, 18 subjects

44% male, 56% female

72% students

5 rounds of 5 – 14 min

payment corresponding to performance

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Results & DiscussionTeam Formation

Result 1

These factors are shown to significantly affect performance:

joining teams (pearson correlation, r = 0.56)

initiating teams (pearson correlation, r = 0.42)

delivering packages individually (pearson correlation, r = 0.31)

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Result 2Subjects showed a preference to interact with those they successfully interacted with before.

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trust historynumber of times subjects successfully

cooperated in the pastin any team configuration

likelihood of future interaction


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Results & DiscussionIntention Reconciliation

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Result 3Trust is more important to the decision of defection than the height of outside offers.

> No significant increase of payoff for accepted outside offers. > Small but significant correlation between accepted outside offers

and trust value of initiator (0.29).

Results & DiscussionParticipant Type

Result 4Players offer humans significantly more fair splits than they offer agents.

(combined t-test, p < 0.0001)to people: avg. 94% fairto agents: avg. 82% fair

100 % fair 50 % fair

2-player team 30 15

3-player team 60 30

Result 5The nature of participants does not significantly affect:1. the choice of team partners2. the acceptance of offers3. defection behavior

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Results & DiscussionParticipant Type

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Conclusions

People are just as loyal and trusting towards agents

as to humans.agent-initiated teamwork and

working alongside autonomous systems(search-and-rescue, personal assistants, decision

support)

People offer agents less, thereby valuing them

differently from humans. agents need to behave and appear

natural and ‘human-like’ (e-commerce, bidding, games, personal assistant)

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Conclusions

People prefer to work with players they have

successfully worked with before. refer to previous interactions,

have memory(games, companions)

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Future Work

1. Computational Model

2. Belief Desire Intention (BDI) Agents

3. Pre-established payoff distributions

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Thank you.

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Game FlowInitiator

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Game FlowInitiator

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Game FlowMember

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Game FlowMember

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Related WorkTrust

For an actor a to be said to trust another actor b with respect to a particular goal g, a must have the following beliefs (castelfranchi, 1998, 2001) :

• Competence Belief: b is useful for achieving g and is able to provide the expected result • Disposition Belief: b is not only capable, but also willing to do what is necessary to achieve g • Dependence Belief: the results and rewards of achieving g depend on the involvement of b • Fulfillment Belief: g will come about due to b’s involvement

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Results & DiscussionNature

Result 7The nature of participants does not significantly affect the choice of team partners or the acceptance of offers.

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Introduction

Types of interactions:- cooperative and helpful interactions- competitive interactions- cooperative interactions in competitive scenarios

non-cooperative games - self-interested actors who can make non-binding

commitments - basic modeling unit is the individual

cooperative games- players can make binding commitments- communication and negotiation between the players is allowed- groups of players (teams) may enforce cooperative behavior

- basic modeling unit is the group

team Formation

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Conceptual Design

Assumptions in CF

Interchangeability

Prev work

All potential members bring the same utility to a team.

Our work

Some potential members are preferred over others.

Membership

Prev work

Membership to a team is equally available to everyone.

Our work

Members have to meet certain requirements for membership to be available to them.

Conflict

Prev work

Conflict is eliminated by making agreements binding.

Our work

No conflict-free environment since agreements are not binding.

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Introduction


The Problem

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What strategy did you use for choosing your team members?

``Whether members were reliable. I could give computers a smaller share without feeling guilty. I did build a good history with one other human player.’’

``I chose the computers mostly, since I thought that they would demand less points.’’

Results & DiscussionNature

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Conceptual Design

Identify the extent to which these factors affect behavior in heterogeneous systems.

Derive principles that designers of such systems could use to construct agents that are able to participate effectively in teams.

How do nature and trust influence people’s decisions

in mixed team formations?

Objective

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Outline

1. Introduction2. Related Work

3. Conceptual Design4. Experimental Design5. The Experiment

6. Results & Discussion7. Conclusions

8. Future Work 9. Contributions

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Results & Discussion

1. Survey

- preferences - strategies

2. Log

- proposals- teams- defections

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Experimental Design

team formation consists of two steps:

1. The initiator invites members who thereafter join the team.

2. The team delivers the package. attempted team

Package Delivery Domain

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i

?

Experimental Design

team formation consists of two steps:


2. The team delivers the package. formed team


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i


Team formation consists of two steps:

1. The initiator invites members who thereafter join the coalition.

2. The coalition delivers the package.

formed teamA team is formed when the initiator has invited the

requiredmembers for a team and the members have agreed to

be part ofthat team.


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1. The initiator invites members who thereafter join the coalition.

2. The coalition delivers the package.

successful teamA successful team is a formed team that succeeded to

delivera large package to the goal.


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2. The team delivers the package.

failed teamAn unsuccessful team is a team that was dissolved (bydefection) before it was able to deliver the package.


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Results & DiscussionIntention Reconciliation

Result 5Players with a high defection rate are as successful as those with a low defection rate.

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Results & Discussionteam Formation

Result 2Players created more 3-player teams than 2-player teams.

(goodness of fit, p < 0.00001)

Result 3No difference in defection rates in 2- and 3-player teams. 57


successful teams frequency

0 1 0 2 0 4 0 5 1 2 11 3 1 5 2 3 2 4 23 4 13 5 4 5 0 1 20 1 50 2 40 4 51 2 3 121 3 52 3 4 23 4 5 1

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Team Formation between Heterogeneous Actors

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