E-commerce

1. Electronic contracts Contract Life-Cycle 1. Contract negotiation Communicative Acts Auctions Negotiation Protocols Contract Formalisation 2. Contract execution Temporal Defeasible logic Contract monitoring Commitment machines Automatic Dispute Resolution Modalities Legal doctrines, Legal rules, Cased based Reasoning, 3. Contract breach Simple disputes E-commerce Argumentation Process Complex disputes

2. A Computational Model for World Wide Argument Web Adrian Groza Technical University of Cluj-Napoca, Department of Computer Science, Adrian.Groza@cs.utcluj.ro 13th Estonian Winter School in Computer Science

3. Outline • World Wide Argument Web (WWAW) • Vision and Application Domains • Argument Interchange Format Ontology • Argumentation schemes • Taxonomy of Schemes • Argumentation Schemes as Protocol • Technologies for enacting WWAW • Conceptual Maps • Planning with Argumentation Schemes • Conclusions

4. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Vision and Application Domains • Argument Interchange Format Ontology Definition: large scale network of inter-connected arguments created by human agents in a structured manner. Queries example in WWAW: • “List all arguments supporting that Estonia had important results at skiing on the 2006 Olympics games.” • “List all the counter arguments attacking the above sentence.” • “List all the economical arguments supporting the feasibility of alternative fuel.” “List the strongestpolitical argument attacking alternative fuel.” • Domains: • legal (online dispute resolution) • medical • education (critical thinking) • e-democracy (deliberative democracy –town planning scenario)

5. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Vision and Application Domains • Argument Interchange Format Ontology Vision • The idea backs its roots in 19971, now reiterated by the outputs of the European ASPIC (Argument Service Platform with Integrated Components) in 20072 • Create an infrastructure for mass-collaborative editing of structured arguments in the style of Semantic Wikipedia • Until now: finding the most suitable logical formalism for modelling argumentation process: • Recently: providing a framework which permits using different types of logical formalisms. Argument Interchange Format Ontology Defeasible logic • Chris Reed. Representing and applying knowledge for argumentation in a social context. AI and Society, 11(1-2):138–154, 1997. • Iyad Rahwan, Fouad Zablith, and Chris Reed. Laying the foundations for a world wide argument web. Artificial Intelligence, 171(10-15):897–921, 2007.

6. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Vision and Application Domains • Argument Interchange Format Ontology • Argument Interchange Format Ontology (AIF) • Aiming to unify the majority of conceptual work in argumentation theory under one umbrella; • Extendable ontology Our computational model Information nodes Scheme nodes PA-node Passive information: claim, premise, data, locution, etc. Preference application node: legis posterior, legis specialis, etc. Conflict application schemes: negation Rule of inference schemes: modus ponens, modus tolens, defeasibile modus ponens, etc. Form-node This presentation PIA-node Extensions: Protocol Interaction Application node (Modgil 2007) Argumentation schemes: argument from expert opinion (Rahwan, 2007) Context application node: social, intentional, dialectical (Letia, 2008)

7. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Taxonomy of Schemes • Argumentation Schemes as Protocol Argumentation Schemes • Capture stereotypical patterns of human reasoning • Fill the gap between logic-based argumentation and human argumentation • Around 200 domain independent schemes (Walton, 1996; Pollock, 1995; Katzav, 2004) Name of the Scheme Critical questions aim to defeat the derivation of the conclusion Ai: set of premises C : a conclusion CQj: set of critical questions

8. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Taxonomy of Schemes • Argumentation Schemes as Protocol • Examples of argumentation schemes • Argument from the sameness of meaning • Argument from common sense • Argument from commitment, Argument from legal rule, Argument from precedent case • Argument from sign, Argument from position to know Argument from expert opinion A1: E is an expert in domain D. A2: E asserts that A is known to be true. A3: A is within D. C: A may (plausibly) be taken to be true. CQ1: Is E a genuine expert in D? CQ2: Is A relevant to domain D? CQ3: Is A consistent with what other experts in D say? CQ4: Has the expert E a good reputation?

9. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Taxonomy of Schemes • Argumentation Schemes as Protocol • An argumentation line p for a claim q is a chain of argument schemes <ASai>, where the last AS has as consequent q, and a represents the agent who instantiated the scheme. • Each argumentation line provides the corresponding CQs that the opponent may use when he wants to challenge the pleading • When a CQ is conveyed the conclusion of the corresponding AS is suspended, until the subject of the dispute is clarified • Whoever is responsible for this clarification (who has the burden of proof) depends on the type of CQ: • Presumptions (undercutting CQ): attacks the link between • the premises and the conclusion. The burden of proof is • shifted to the proponent of the argument. • 2. Exceptions (rebuttal CQ): challenges an argument by • instantiating an AS sustaining the opposite conclusion. • The burden of proof remains to the opponent.

10. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conceptual Maps • PDDL Conceptual Maps • Used to provide intuitive visualisation of the argument networks to the human agent • Diagramming reasoning • Small scale: Araucaria, Rationale, Compendium, Athena, Belvedere • Cmapservers • Deploying arguments in WWW; • Searching arguments within public argument maps; • Sharing argument maps

11. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conceptual Maps • PDDL

12. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conceptual Maps • PDDL

13. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conceptual Maps • PDDL • Requirements: • Richness of knowledge representation • Semantic web compatibility • Metrics to compare arguments chains • The classical approach for proving a sentence is to use an inference engine • Our approach: each argumentation scheme is implemented as an action (operator) within a planning domain We use PDDL (Planning Domain Definition Language)

14. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conceptual Maps • PDDL • PDDL advantages: • It is very expressive having different levels of richness: types, probabilities, time constraints • It is supported by a wide range of planning engines: the most suitable planner for the problem in hand can be use: • Explanations: abductive planner (Shannon) • High complexity: hierarchical task decomposition planner (D. Nau) • Strong debate: defeasible planner (Pollock) • The mediation protocol can be encapsulated in preconditions and effects, while consequents in conditional effects • Several metrics for comparing argument chains • The scheme taxonomy can be extended within planning domains depending on the mediator experience • Through Web-PDDL and PDDL2OWL the framework is compatible with the semantic web

15. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conceptual Maps • PDDL (define (domain OnlineDisputeResolution) (:requirements :typing :adl) (:types as cq category fact agent – object mediator debtor creditor expert – agent) (:constants AS_EXPERT AS_COMMITMENT – as AS_EXPERT_CQ1, AS_EXPERT_CQ2 – cq) (:predicates (expert ?e – expert ?d – category claim ?e expert ?x - fact ………. (:actionclaim_AS_EXPERT :parameters (?a - agent ?e – expert ?d – category ?x – fact) :precondition (and (legal AS_EXPERT) (burdenOfProof ?a)) :effect (when (and (expert ?e ?d) (claim ?e ?x) (belongs ?x ?d)) (and (plausibility ?x) (legal AS_EXPERT_CQ1) (legal AS_EXPERT_CQ2) Protocol Rules Argumentation Scheme

16. World Wide Argument Web Argumentation Schemes Technologies for Enacting WWAW Conclusions • Conclusions • Identifying technologies for enacting WWAW • Conceptual Maps for AIF ontology • PDDL for encapsulating Argumentation schemes (F-node) and protocols (PIA-node) • Research issues: context aware argumentation, re-utilizability of arguments. • WWAW in the style of Wikipedia. Thank you !