Preparing for Melbourne

About social commitments(of)

Frank Dignum

Contents

• (Social) commitments• Use of commitments in AC• Nature of commitments• “Definition”• Use in AC• Commitment strategies• Conclusions

Commitments in agents

• Cohen & Levesque (commitment strategy)– (P-GOAL x p) ≡ (GOAL x (LATER p)) (BEL x ¬p)

[BEFORE ((BEL x p) (BEL x □ ¬p)) ¬(GOAL x (LATER p))]

• Rao & Georgeff (commitment strategy)– INTEND(inevitable◊Φ) inevitable(INTEND(inevitable ◊Φ)

BEL(Φ))

Social commitments

• Castelfranchi– (S-COMM x y z a) (OUGHT x (DOES x a))– (HONEST x) = (S-COMM x y z a) (I-COMM x a)

• Singh– P-commitment– S-commitment

(beliefs and actions)

Semantics of Agent Communication

<i, inform(j,X)>FP: BiX Bi(BjX BjX UjX UjX)RE: BjX

Problem: How to check the beliefs of the agents? They are private and not accessible

from the outside.

Social Commitments in Agent Communication

• [inform(x,y,p)] SC(x,y,p)

• [promise(x,y,)] SC(x,y,)

• A speech act leads to a social commitmentwhich is visible from outside.

• Walton & Krabbe use “commitment stores”

Some questions• What are the consequences for an agent when it

has a social commitment?• Connection between mental attitudes and

commitment?

• Connection between social and private commitment?

• Connection between commitments and norms/obligations?

• Committing vs. commitment

Commitment

Definitions (Webster’s, Wordweb):1. The act of binding yourself

(intellectually or emotionally) to a course of action or a purpose

2. A (message that makes a) pledge or promise

Commitment

• Mental attitudes involved• Choice should be possible

– Knowledge vs. belief• Degrees of commitment

– When to abandon a commitment?• Little possibilities for revision• Many supports that should be revised• Rf. Epistemic entrenchment

Commitment• A commitment of an agent to a mental attitude

(like belief, goal or intention) is the degree to which the agent is prepared to stick to the choice by which she created that mental attitude.

• COMMIT(x,ma,d)– ma := Bx(Φ) | Gx(Φ) | INTx()– d (0,1]

• We assume: – Bx(Φ) COMMIT(x, Bx(Φ),d)– Gx(Φ) COMMIT(x, Gx(Φ),d)– INTx() COMMIT(x, INTx(),d)

Commitment

• Primary citizen or derived?• Is commitment merely calculated from an

existing web of mental attitudes?• I.e. is it an intrinsic aspect of every mental

attitude?

• Or can we have a commitment and derive some mental attitudes from it?

Social Commitment

• SOC-COMMIT(x,y,ma,d) ≡ COMMIT(x, ma,d) Ox,y(ma)

• The private part of a social commitment is a private commitment which is made under complete autonomy by the agent

• The social or public part of a social commitment is an obligation!

Social Commitment

• The obligation in a social commitment comes about by an act of the agent that is obliged.

• Therefore it is often assumed that that agent is also having a commitment

• But this needs not be true!

Social Commitment and AC• [inform(x,y,p)] Ox,y(B(x,p))

• [promise(x,y,)] Ox,y(INT(x, ))

• The resulting obligation might lead to a decision to create or increase a commitment to the mental attitude.

• So, a speech act leads to an obligation• Only when an agent is sincere it will lead to a

social commitment.

Example I• INFORM(x,y,“the weather in Melbourne is nice”)• Now y infers Ox,y(B(x,”the weather in Melbourne is nice”)) • Suppose ¬B(x,”the weather in Melbourne is nice”)

•It seems x created a dichotomy between its mental states and obligations. This will lead to “stress” in subsequent conversations.

•Because x voluntarily and autonomously provided the information and we assume that x tries to avoid unnecessary violations/”stress” we usually conclude that x also is committed to what it says.

Example II• INFORM(x,y,“this car is nice”)• Now y infers Ox,y(B(x,”this car is nice”)) • Suppose ¬B(x,”this car is nice”)• Now x continues:• INFORM(x,y,”you can buy it for only є10.000”)• x created a dichotomy between its mental states

and obligations for a reason! The information is needed to support his subsequent offer.

• In this situation we still belief that x has an obligation to belief what he said, but we do not assume that he actually believes it!

Connection between Social Commitment and mental attitudes

• Ox,y(B(x,p)) ¬B(x,p) Violation

• However, the violation cannot be detected from the mental attitude directly!

• Only acts from which this belief can be inferred can be used to detect a violation.

• E.g. inform(x,y,¬B(x,p)), or a failure to defend B(x,p) in an argumentation

Conclusions

• Commitments are private• Obligations are public (and

can be committed to)• Commitments say more

about the change of mental attitudes than that they are mental attitudes themselves

• There is a lot of future work to do (in Melbourne)