1 Intelligent Agents Software analog to human agents real estate agent, librarian, salesperson Perform tasks individually, or in collaboration Static and mobile Communicate via messages or not Learn preferences over time

2 Working definitions An agent is a reusable software component that provides controlled access to (shared) services and resources. Example: a printer agent that provides printing services schedules requests to a shared printer. Agents are the basic building blocks for applications, and applications are organized as networks of collaborating agents. Example: a desktop agent "recruits" the services of a screen and a connection agent to physically connect a call. The behavior of each agent is constrained by policies which are set by higher-level agents (security, load balancing, user prefs etc.). Example: 60% of the calls over a trunk are made by one user agent.

3 Differences from conventional programs Agents are autonomous, that is they act on behalf of the user Agents contain some level of intelligence, from fixed rules to learning engines that allow them to adapt to changes in the environment Agents don't only act reactively, but sometimes also proactively Agents have social ability, that is they communicate with the user, the system, and other agents as required Agents may also cooperate with other agents to carry out more complex tasks than they themselves can handle Agents may move from one system to another to access remote resources or even to meet other agents

4 Usage Simplifying distributed computing Agents as intelligent resource managers Overcoming user interface problems Agents as personal assistants which adapt to the user This is another important motivation for agent research: convergence in AI research.

5 Nwana's classification 1. Mobility: static or mobile 2. Reasoning model: deliberative or reactive 3. Ideal attributes: autonomy, learning and cooperation 4. Role: information, management 5. Hybrid: combination of the above Source: H. Nwana, Software Agents: An Overview

6 Nwana's classification

7 Architecture

8 Collaborative agents Modular (eg, interface, task and information agents) Agents negotiate in order to resolve conflicts (eg, meeting time) Some agents collaborate to integrate information Agents wrap around legacy systems ("glue" to interconnect them) Provide solutions to inherently distributed problems airtraffic control telecommunications network management

9 RETSINA Collaboration model

10 Interface Agents Support and provide assistance. Cooperates with the user in accomplishing some task in an application. Interface agents learn: by observing and imitating the user (from user) through receiving feedback from the user by receiving explicit instructions by asking other agents for advice (from peers) Filters (eg, your ) Eager assistant (eg Open Sesame) Social filtering (referrals)

11 Information Filtering Individual Recommendation Agents Fine grained (users treated as individuals) Driven by attributes of users and products, therefore can recommend new products WebWatcher

12 Collaborative Filtering CF: Items I interacted with are compared to Items other people interacted with Assumes you are like others (requires others) Requires interaction history prior to recommendation Amazon.com, Group Lens

13 Interface Agents

14 Information Agents Manage the explosive growth of information. Manipulate or collate information from many distributed sources. Examples: intelligent wrappers. Challenge: ontologies for annotating Web pages (eg, SHOE). Information agents can be mobile or static.

15 Information Agents

16 Mobile agents Programs that can migrate from one machine to another. Execute in a platform-independent execution environment (requirement of places). Practical but non-functional advantages: Reduced communication cost (eg, from PDA) Asynchronous computing (when you are not connected) Two types: One-hop mobile agents (migrate to one other place) Multi-hop mobile agents (roam the network from place to place) Applications: Distributed information retrieval. Telecommunication network routing.