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Tutorials IMPORTANT NOTICE: Participants that are attending a workshop or tutorial on Monday should register on Sunday from 4pm till 7pm. T1. Multiagent Organizations Jaime Simao Sichman, Olivier Boissier, and Virginia Dignum In the last years, social and organizational aspects of agency have become a major issue in MAS research. Recent applications of MAS on Web Services, Grid Computing and Ubiquitous Computing enforce the need of using these aspects in order to ensure some social order within these systems. One of the ways to assure such a social order is through the so-called multiagent organizations. Multiagent organizations are of two types: either the organization emerge from the activity of the individual agents or it is designed to facilitate and guide some specific global behavior, In the latter case, systems are characterized by the autonomy of the individual participants that however must be able to collaboratively achieve predetermined global goals, within a globally constrained environment. However, there is still a lack of a comprehensive view of the diverse concepts, models and approaches related to multiagent organizations. Moreover, most designers have doubts about how to put these concepts in practice, i.e., how to program them. This tutorial, addressed to active practitioners, graduate and senior undergraduate students, aims at giving an answer to such questions. T2. Trust and Reputation in Multiagent Systems Guillaume Mullerand Laurent Vercouter The tutorial begins with an introduction of the general motivations of trust in multiagent systems. The typical problems tackled by trust and reputation model are presented. We show that they are different problems than the ones tackled by security techniques and that security and trust must be considered as complementary approaches. The foundations of trust models are then explained. Starting from sociological studies, we identify the main concepts involved in trust models. Clear definitions of concepts such as trust, reputation, recommendation, ... are given using the typology proposed by L. Mui (2002) and the functional ontology of reputation proposed by S. Casare (2005). A survey of the main reputation models is presented. This survey starts from simple models based on a central repository of feedbacks as the ones used in ecommerce web site such as ebay or OnSale and the Sporas and Histos models (Zacharia et al.). Reputation models that include an automatic decision process are then described (models from AbdulRahman et al. and from Marsh). At last, the most elaborated models that implement a complete automatic evaluation and reasoning process are presented: the models proposed by Sen et al., by Schillo et al., by Wang et al., the Liar model proposed by Muller et al. the Regret model proposed by Sabater and Sierra and the Repage model proposed by Paolucci, Sabater and Conte. At the end of this first part of the tutorial, we summarize the current state of the art and we present the current challenges that future research in the field of trust and reputation should aim. The third part of the tutorial is dedicated to a presentation and a demonstration on the ART testbed (Fullam et al.). The problem of the wide heterogeneity of reputation models is stated and the ART testbed is presented as a tool to allow the experimentation and the comparison of different models. The architecture and the functioning of ART are described. The end of this last part of the tutorial is dedicated to practice on the ART testbed. We will present step by step how to build a simple agent able to participate in an ART competition. The idea is to provide the participants with the essential tools so they can be future participants in the ART international competition. T3. Programming Languages and Development Tools for Multiagent Systems Rafael H. Bordini, Mehdi Dastani, Koen Hindriks, Joao Leite With the significant advances in the area of autonomous agents and multi-agent systems in the last few years, promising technologies have emerged as a sensible alternative for the design of systems that can operate in complex and dynamic scenarios. However, in order for this technology to become accessible to the multi-agent research community in Academia and practitioners in Industry, it is necessary that programming languages and tools that are appropriate for developing such systems become widely known and thoroughly understood. This course aims at introducing novices, researchers, and developers (from both Academia and Industry) who already have basic notions of multi-agent systems to some of the languages, techniques, and tools that are currently available to support the effective implementation of multi-agent systems. T4. WADE: An Open Source Platform for Workflows and Agents Giovanni Caire The tutorial shows how to use WADE to develop distributed applications based on the agent paradigm and exploiting the workflow metaphor to define system logics. WADE is the evolution of JADE (http://jade.tilab.com) a popular Open Source agent oriented middleware that provides, among others, the Agent and Behaviour abstractions, peer-to-peer communication between agents and publish/subscribe agent discovery mechanisms in compliance with the FIPA specifications (www.fipa.org). WADE goes further providing a number of additional mechanisms to facilitate the administration of a highly distributed application, but most of all gives JADE agents the ability to execute tasks defined according to the workflow metaphor. Nowadays workflows are mostly adopted in BPM (Business Process Management) environments where they are used to represent business processes and orchestrate existing systems typically (but not necessarily) accessible by means of Web Services-based interfaces. The main challenge in WADE is to bring the workflow approach from the business process level to the level of system internal logics. That is, even if in principle it could be used for that purpose too, WADE does not target high level orchestration of services provided by different systems, but the implementation of the internal behaviour of each single system. Each agent embeds a micro-workflow engine and a complex process can be carried out by a set of cooperating agents each one executing a piece of the process. Attendees will initially get an overview of the advantages of the workflow metaphor and the requirements that a system must meet to make its adoption fruitful at the level of system logics definition. After that they will start familiarizing with the WADE platform and understand how to structure a WADE-based application. In the core part of the tutorial attendees will learn how to create workflows by means of WOLF (the Service Creation Environment provided by WADE) and to make agents execute them. Particular attention will be given to the mechanisms that WADE provides to make the workflow approach suitable for system logics definition. Finally an overview of advanced features such as transactions support will be given and the evolutions planned for the near future will be presented. T5. Fair Division Ulle Endriss Resource allocation has always been a central topic of concern in the multiagent systems research community. Mechanisms for dividing a set of goods amongst several agents need to balance (economic) efficiency and fairness requirements. For instance, for an allocation to be efficient we may want it to maximise the sum of individual agent utilities, while a common interpretations of fairness is envy-freeness: no agent should prefer someone else's bundle of goods to their own lot. While efficiency issues are routinely being addressed in multiagent systems research, fairness is only just starting to receive broad attention. It is therefore important to expose this community to classical work on fair division, and to advance research in fair division by adding a multiagent systems perspective. The classical example from the fair division literature is the problem of dividing a cake (a single divisible good) amongst several players, while recent work in multiagent resource allocation has mostly concentrated on the allocation of sets of indivisible goods, which gives rise to a combinatorial optimisation problem. This tutorial will be an introduction to the area of fair division, with an emphasis on computational considerations. Specifically, we will give an overview of fairness and efficiency criteria of interest to multiagent systems and discuss their axiomatic foundations; we will review the most important contributions to the literature on cake-cutting from an algorithmic point of view; and we will discuss distributed approaches to the fair allocation of indivisible goods in multiagent systems. Further information is available here. T6. Agent-Mediated Electronic Negotiation (Part 1) Han La Poutre and Valentin Robu This tutorial aims to give a broad overview of state of the art in agent-mediated negotiation. The first part of the tutorial will focus on the game-theoretic foundations of electronic negotiations. We review the main concepts from both cooperative and competitive bargaining theory, such as Pareto optimality, the Pareto-efficient frontier as well as utilitarian, Nash and Kalai-Smorodinsky (egalitarian) solution concepts. We discuss and compare games with complete and with incomplete information. Next, we exemplify these concepts through a well-known sequential bargaining game, such as the ultimatum game. A particular emphasis will be placed on multi-issue (or multi-attribute) negotiation - a research area that has received significant attention in recent years from the multi-agent community. We discuss and illustrate some of the challenges that arise in modeling bilateral and multilateral negotiations over multiple issues, especially when no information (or only incomplete information) is available about the preferences of the negotiation partner(s). n the second part of the tutorial we present some of the heuristics employed in AI and machine learning research for the agent-mediated negotiation problem. We discuss how different techniques, such as evolutionary computing, neural networks or graph-theoretic models can be used to model the bargaining problem. The tutorial is concluded with an overview of the possible application areas for agent-mediated negotiation techniques, ranging from electronic commerce supply chain management, distributed logistics and e-healthcare. More information about this tutorial is available at: T7. Complex negotiations for Intractable Problems (Agent-Mediated Electronic Negotiation-Part 2) Takayuki Ito, Shaheen Fatima and Hiromitsu Hattori This tutorial aims to give a broad overview of multi-agent complex negotiations for intractable negotiation problems. This tutorial will be the 2nd part of the workshop on Agent-mediated electronic negotiation. Thus the audience should be familiar with with very basic notions of agent-mediated electronic negotiation, as covered in the overview in part 1 of the tutorial. Here we look, in more depth, the following important issues in electronic negotiation. One of the most important notion in intractable negotiation problem is "multi-issue negotiation". Part 1 will show the brief overview of multi-issue negotiation. In this Part 2, we especially focus on multi-issue negotiations which may have realistic limitations like time-constraints, computational tractability, private information issues, online negotiations, etc. T8. Decision-Making in Extended Multiagent Interactions Prashant Doshi and Zinovi Rabinovich Choosing optimally among different lines of actions is a key aspect of autonomy in agents. The process by which an agent arrives at this choice is complex, particularly in environments shared with other agents. This tutorial will focus on how to make optimal and approximately optimal decisions in multiagent settings. The tutorial will utilize the well-studied domain of search and human support applications to motivate and provide context for a range of multiagent interactions of increasing generality. The focus of this tutorial will be on decision-making in time extended interactions, which are often encountered in search and human support applications. The tutorial will adopt a unique pedagogical style, utilizing several classroom games to generate intuition and reinforce instruction. The tutorial will be self-contained, introducing relevant background literature such as aspects of game theory. Tutorial flyer available here. T9. Argumentation for Managing Communities of Agent-Based Web Services Jamal Bentahar and Zakaria Maamar The purpose of this tutorial is to discuss the way communities of Web services could be managed using argumentation. A community is primarily set-up to gather Web services with similar functionalities regardless of who developed these Web services, where these Web services are developed, and how these Web services function. Current practices in the field of Web services assume that a community is static and Web services in a community exhibit always a cooperative attitude. These practices need to be revisited as per the following arguments. A community could be made dynamic: new Web services enter, other Web services leave, some Web services become temporarily unavailable, and some Web services resume operation after suspension. All these events need to be closely monitored so that inconsistent situations are avoided. Moreover, Web services in a community could compete on non-sharable computing resources, which may delay their performance scheduling. Web services could also announce misleading information ( e.g., non-functional details) in order to boost their participation opportunities in composition scenarios. Finally, Web services could be malicious so they try to alter other Web services' data and operations. Making Web services communities active by associating argumentative agents with Web services populating these communities could take advantage of the research findings in the field of multi-agent systems with focus on argumentation. An argumentative agent complies with a dialectical process when it aims at affirming or disavowing conclusions that it aims to convey to peers. Associating Web services with argumentative agents would enable these Web services among other things to make decisions and persuade each other about entering a community, leaving it after awhile, and re-entering it if some business opportunities loom. This will also enable Web services to negotiate rewards for being part of a community, and to negotiate participation in composite Web services. These mechanisms would be developed along three perspectives: 1. Community management: how to establish/dismantle a new/existing Because agent-based Web services and argumentation are topics of emerging importance within the AAMAS community, this tutorial aims at motivating these topics, explaining how they relate to each other, and identifying new directions of research that could interest AAMAS attendees. The tutorial also aims at introducing novices to these topics and at surveying the area of Web services-based on multi-agent systems. T10. Verification of Multiagent Systems via Symbolic Model Checking Alessio Lomuscio and Wojciech Penczek The tutorial will last 4 hours and will cover part of the work the applicants have been directly involved in for the past 5 years, as well as summarise of other results available in the literature. The tutorial intends to provide both the theoretical background, as well as a hands-on introduction to two model checkers available in the area. The overall objective is to enable the participant to achieve a basic understanding of the technology and to provide pointers to further results and open problems for further research. While the course will focus on the speakers' outputs discussion with alternative approaches will constantly feature in the tutorial.
Monday 12th, Morning T3: Programming Languages and Development Tools for MultiAgent Systems (Full Day) Monday 12th, Afternoon T3: Programming Languages and Development Tools for MultiAgent Systems (Full Day) Tuesday 13th, Morning T6: AgentMediated Electronic Negotiation (Part 1) Tuesday 13th, Afternoon T7: AgentMediated Electronic Negotiation (Part 2)
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