Agents Computer Programs of a certain type Effectively bodiless robots –Rise of internet enables Agents Lostness –As life becomes more complex, we cannot keep up with it –We’re lost in over-complex world –Agents can perform work on our behalf

Autonomy Agents are autonomous Make own decisions –E.g. buying agent may decide when to purchase goods, and arrange for them to be delivered Agents may need considerable intelligence so that they can make good decisions

Persistent Existence Agents exist “over time” –Disk space compression agent may be running all the time our computer is on –Purchasing agents started running, may run for weeks while waiting for best price –Mobile agents may be running even when our computer is off Return to ‘base’ at later time

Pro-Active Agents decide themselves when to act, in pure form without impetus from user Agents may act due to a number of triggers –user events –system events –changes in status –timed events –other agent events

Communicative Agents able to communicate Most interesting, communication between programs from different sources –E.g. buying agent for user X negotiating price with supplier agent for company Y More generally, may communicate to solve problems KQML - defined wrapper for messages

Economic Potential Benefit from user’s point of view –Price comparison without wasting user’s time Benefit for industry –Able to tap into growing Agent marketplace Scale of agent-related commerce –$357million in 1998 –Est. $4.6billion in 2006

Blackboard System

Message Passing

Match-Making

Brokering

Static Agents Remain in one place –E.g. user’s or remote computer –May communicate with outside world E.g. TutorAgent –Remote Program Calls –Remote Method Invocation (Java) Relatively few security problems

Mobile Agents Agents themselves may move E.g. Agent may leave your computer and visit computers of several airlines Generally need way of packaging up code and transporting Need machine/OS independent execution environment (Java, Telescript)

Security Problems with Mobile Agents Danger to Machine Rogue agents –Agents may attack machines they visit –Agents may carry digital signatures Rogue hosts –Host may attack agent –E.g. change prices so that host appears cheapest

Agents and Information Search Major application for agents search for information –E.g. tutoragent, searches for resources on web relevant to on-line lecture notes Stanford Digital Library project –Uses commerce model for non-commercial application(!)

Agents and E-Commerce Need Identification Product brokering –Firefly Merchant brokering –Bargainfinder Negotiation –Kasbah Product service

Recommender Systems Content-Based –Try to extract knowledge from source based upon human orientated knowledge Constraint-Based –Complex set of constraints defining product wanted including ‘soft’ constraints Collaborative Based –Try to analogise from the experience of others

Virtual Markets Virtual Marketplace –Agents created by different users will try to buy and sell products –Follow predefined strategy to maximise value for user Virtual Auctions –Very interesting and challenging area Especially useful for second-hand goods –Note: A lot of ‘new’ products sold on ebay

Agent Negotiation Protocols –Rules of Virtual Marketplace –E.g. Dutch Auction –Apply to all agents Strategies –rational strategy to maximise utility function –relevant to individual agents

Agent Negotiation II Economics Research –Research equilibrium of market based negotiation –Nature of protocols affects equilibrium Game Theory –Emphasis on protocols and self-interested strategies –Self-interested strategies can have weird effects in Agent “mob psychology”

Agent Negotiation III Distributive Negotiation –Single sized pie distributed among people –E.g. Kasbah Integrative Negotiation –Try to increase size of pie through negotiation