Tuesday 30 October 2007

Requirements on Commitment in Dialogue

Taken from 'Fundamentals of Critical Argumentation' (2006), by Douglas Walton

Three General Requirements on Commitment in Dialogue

1, If a proponent is committed to a set of statements, and the respondent can show that another statement follows logically as a conclusion from that set, then the respondent is committed to that conclusion.

2, The respondent has the right to retract commitment to that conclusion, but she must also retract commitment to at least one of the premises. For otherwise it has been shown that she has inconsistent commitments.

3, If one party in a dialogue can show that the other party has inconsistent commitments, then the second party must retract at least one of those commitments.

Inconsitency is generally a bad thing in logic. If a set of statements is inconsistent, they cannot all be true. At least one must be false...

34, A Verifiable Protocol for Arguing about Rejections in Negotiation

Notes taken from 'A Verifiable Protocol for Arguing about Rejections in Negotiation' (2005), by Jelle van Veenen and Henry Prakken

1, Introduction

2, Negotiation and Argumentation

Speech acts and replies in negotiation with embedded persuasion:


Act: request(a)
Attacks: offer(a'), withdraw

Act: offer(a)
Attacks: offer(a') (a /= a'), reject(a), withdraw
Surrenders: accept(a)

Act: reject(a)
Attacks: offer(a') (a /= a'), why-reject(a), withdraw

Act: accept(a)

Act: why-reject(a)
Attacks: claim(¬a), withdraw

Act: withdraw


Act: claim(a)
Attacks: why(a)
Surrenders: concede(a)

Act: why(a)
Attacks: argue(A) (conc(A) = a)
Surrenders: retract(a)

Act: argue(A)
Attacks: why(a) (a is in prem(A)), argue(B) (B defeats A)
Surrenders: concede(a) (a is in prem(A) or a = conc(A))

Act: concede(a)

Act: retract(a)

The speech acts above show the combination of languages for negotiation and persuasion. The negotiation is extended with the why-reject locution, which allows a negotiation to shift into a persuasion subdialogue.

3, An Example

4, Conclusion

Illocutions for Persuasive Negotiation (2)

The dialogue primitives (performatives) described in 'Logic agents, dialogues and negotiation: an abductive approach' (2001) are of the form tell(a,b,Move,t) where a and b are the sending and the receiving agents, respectively, t represents the time when the primitive is uttered, and Move is a dialogue move, recursively defined as follows:

- request(give(R)) is a dialogue move, used to request a resource R;

- promise(give(R),give(R')) is a dialogue move, used to propose and to commit to exchange deals, of resource R' in exchange for resource R;

- if Move is a dialogue move, so are
--- accept(Move), refuse(Move) (used to accept/refuse a previous dialogue Move)
--- challenge(Move) (used to ask a justification for a previous Move)
--- justfiy(Move) (used to justify a past Move, by means of a Support)

There are no other dialogue moves, except the ones given above.

Monday 29 October 2007

Illocutions for Persuasive Negotiation (1)

In the paper 'A Framework for Argumentation-Based Negotiation' (1997) the authors (Carles Sierra et al) discuss three types of illocutions that serve a persuasive function in negotiation:
(i) threats — failure to accept this proposal means something negative will happen to the agent;
(ii) rewards — acceptance of this proposal means something positive will happen to the agent; and
(iii) appeals — the agent should prefer this option over that alternative for this reason.

The illocutionary acts can be divided into two sets, corresponding to negotiation particles (those used to make offers and counter offers) (offer, request, accept, reject) and corresponding to persuasive particles (those used in argumentation) (appeal, threaten, reward).

The negotiation dialogue between two agents consists of a sequence of offers and counter offers containing values for the issues. These offers and counteroffers can be just conjunctions of ‘issue = value’ pairs (offer) or can be accompanied by persuasive arguments (threaten, reward, appeal). ‘Persuasion’ is a general term covering the different illocutionary acts by which agents try to change other agent’s beliefs and goals.

appeal is a particle with a broad meaning, since there are many different types of appeal. For example, an agent can appeal to authority, to prevailing practice or to self-interest. The structure of the illocutionary act is
where a is the argument that agent x communicates to y in support of a formula f.

threaten and reward are simpler because they have a narrower range of interpretations. Their structure,
is recursive since formulae f1 and f2 again may be illocutions. This recursive definition allows for a rich set of possible (illocutionary) actions supporting the persuasion.

Agents can use the illocutions according to the following negotiation protocol:
1. A negotiation always starts with a deal proposal, i.e. an offer or request. In illocutions the special constant ‘?’ may appear. This is thought of as a petition to an agent to make a detailed proposal by filling the ‘?’s with defined values.
2. This is followed by an exchange of possibly many counter proposals (that agents may reject) and many persuasive illocutions.
3. Finally, a closing illocution is uttered, i.e. an accept or withdraw.


In the paper 'Arguments, Dialogue, and Negotiation' (2000) the authors (Leila Amgoud et al) present a number of moves, describe how the moves update the Commitment Stores (the update rules), give the legal next steps possible by the other agent after a particular move (the dialogue rules), and detail the way that each move integrates with the agent’s use of argumentation (the rationality rules). The moves are classified as follows:

(i) Basic Dialogue Moves (assert(p), assert(S), question(p), challenge(p));
(ii) Negotiation Moves (request(p), promise(p => q));
(iii) Responding Moves (accept(p), accept(S), accept(p => q), refuse(p), refuse(p => q)).

The authors argue that this set of moves is sufficient to capture the communication language of the above-discussed paper.

Tuesday 16 October 2007

33, Getting To Yes

Contents of 'Getting to Yes: Negotiating Agreement Without Giving In' (1992), Roger Fisher and William Ury

I - The Problem
1, Don't Bargain Over Positions

II - The Method
2, Separate the PEOPLE from the Problem
3, Focus on INTERESTS, Not Positions
4, Invent OPTIONS for Mutual Gain
5, Insist on Using Objective CRITERIA

III - Yes, But...
6, What If They Are More Powerful? (Develop Your BATNA - Best Alterative To a Negotiation Agreement)
7, What If They Won't Play? (Use Negotiation Jujitsu)
8, What If They Use Dirty Tricks? (Taming the Hard Bargainer)

IV - In Conclusion

V - Ten Questions People Ask About Getting To Yes

Saturday 13 October 2007

Breaking through the Kyoto impasse

Below is a selection of passages from an article found in the September 29th 2007 issue of 'The Economist', followed by some thoughts.

Section: Economics focus
Title: Playing games with the planet
Subtitle: A version of the "prisoner's dilemma" may suggest ways to break through the Kyoto impasse

"... all countries will enjoy the benefits of a stable climate whether they have helped to bring it about or not. So a government that can persuade others to cut their greenhouse-gas emissions without doing so itself gets the best of both worlds: it avoids all the expense and self-denial involved, and yet still escapes catastrophe...

The problem, of course, is that if everyone is counting on others to act, no one will, and the consequences could be much worse than if everyone had simply done their bit to begin with. Game theorists call a simplified version of this scenario the 'prisoner's dilemma'...

Pessimistic souls assume that the international response to climate change will go the way of the prisoner's dilemma. Rational leaders will always neglect the problem, on the grounds that others will either solve it, allowing their country to become a free-rider, or let it fester, making it a doomed cause anyway. So the world is condemned to a slow roasting, even though global warming could be averted if everyone co-operated.

Yet in a recent paper, Michael Liebreich, of New Energy Finance, a research firm, draws on game theory to reach the opposite conclusion. The dynamics of the prisoner's dilemma, he points out, change dramatically if participants know that they will be playing the game more than once. In that case, they have an incentive to co-operate, in order to avoid being punished for their misconduct by their opponent in subsequent rounds.

The paper cites a study on the subject by an American academic, Robert Axelrod, which argues that the most successful strategy when the game is repeated has three elements: first, players should start out by co-operating; second, they should deter betrayals by punishing the transgressor in the next round; and third, they should not bear grudges but instead should start co-operating with treacherous players again after meting out the appropriate punishment. The result of this strategy can be sustained co-operation rather than a cycle of recrimination.

Mr Liebreich believes that all this holds lessons for the world's climate negotiators. Treaties on climate change, after all, are not one-offs. Indeed, the United Nations is even now trying to get its members to negotiate a successor to its existing treaty, the Kyoto Protocol, which expires in 2012. Many fear that the effort will collapse unless the laggards can be persuaded to join in. But the paper argues that rational countries will not be deterred by free-riders. They will continue to curb their emissions, while devising sanctions for those who do not.

Under lock and Kyoto
The Kyoto Protocol already embodies some of these elements. Countries that do not meet their commitments, for example, are supposed to be punished with a requirement to cut their emissions more sharply the next time around. But Mr Liebreich argues that there should also be sanctions for rich countries that refuse to participate, and stronger incentives for poor countries (which are exempted from any mandatory cuts) to join in...

The global regime on climate change, Mr Liebreich believes, should also be revised more frequently, to allow the game to play itself out more quickly. So instead of stipulating big reductions in emissions, to be implemented over five years, as in Kyoto, negotiators might consider adopting annual targets. That way, co-operative governments know that they cannot be taken advantage of for long, whereas free-riders can be punished and penitents brought back into the fold more quickly.

There are flaws in the analogy, of course. In the real world, governments can communicate and form alliances, which makes the dynamics of the game much more complicated. And governments may not act consistently or rationally... most countries' willingness to act is presumably linked to the severity of global warming's ill effects. If things get bad enough, then with any luck everyone will play the game."

Why is it important to me and my research? It sure makes for an interesting agent problem: A scenario of cyclic dependency, where each agent requires something from another and there is a long-term benefit for mutual collaboration but collaborating requires short-term loss and carries the risk of deceit.