Intelligent Agents

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What is an Agent?• The main point about agents is they are

autonomous: capable of acting independently, exhibiting control over their internal state

• Thus: an agent is a computer system capable of autonomous action in some environment in order to meet its design objectives

SYSTEM

ENVIRONMENT

input output

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Reactivity• If a program’s environment is guaranteed to be fixed, the

program need never worry about its own success or failure – program just executes blindly– Example of fixed environment: compiler

• The real world is not like that: things change, information is incomplete. Many (most?) interesting environments are dynamic

• Software is hard to build for dynamic domains: program must take into account possibility of failure – ask itself whether it is worth executing!

• A reactive system is one that maintains an ongoing interaction with its environment, and responds to changes that occur in it (in time for the response to be useful)

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Proactiveness• Reacting to an environment is easy (e.g.,

stimulus response rules)• But we generally want agents to do things

for us• Hence goal directed behavior• Pro-activeness = generating and attempting

to achieve goals; not driven solely by events; taking the initiative

• Recognizing opportunities

Why intelligent agents?

• Everyday tasks become computer-based

• An increasing number of untrained users using computers

• Current human-computer interfaces require users to initiate all tasks and

monitor them - manually

• Intelligent agents engage in a cooperative process with the user to leverage the

effectiveness and efficiency of human-computer interaction

• Staggering growth in information availability

• Intelligent agents can be a tool for relieving the user of this information overload

• Intelligent agents can act as personal assistants to the user to manage

information

• Might one day take over routine tasks in personal management such as

appointments, meetings and travel arrangements

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What intelligent agents can do for us

• Carry out tasks on the user’s behalf• Train or teach the user• Help different users collaborate• Monitor events and procedures

• Specifically, intelligent agents can help us with– Information retrieval– Information filtering– Mail management– Recreational activities – selection of

books, music, holidays– Booking of meetings, hotels, tickets

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What intelligent agents can do for us (cont’d)

Information filtering agent• One type is the selection of articles from a continuous

stream to suit particular user needs

• User can create “news agents” and train them by giving positive or negative feedback for articles recommended

• The use of key words alone can be restrictive• Underlying semantics must be extracted for more

effectiveness• Eg VPOP Technologies' Newshub - an automated, agent-

based web news feeder service, which delivers customised updates of stories from major news outlets every 15 minutes

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What intelligent agents can do for us (cont’d)

Electronic mail agent • Assist users with electronic mail• Learn to prioritize, delete, forward, sort and archive mail

messages on behalf of the user• May use intelligent system techniques like case-based

reasoning• Can associate a level of confidence with its action or

suggestion• Use of “do-it” and “tell-me” thresholds set by user• May involve multi-agent collaboration

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What intelligent agents can do for us (cont’d)

Selection agents for entertainment• Conversational agents show potential for

becoming popular and commercially successful eg Cybelle, ALICE

• Use “social filtering” – correlation between different users to make recommendations on books, CDs, films etc.

• So, if user A liked items X and Y, and user B liked item X and Z, then item Z may be recommended for user A

• Amazon.com has been using this system for years ->

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Hi, I am Cybelle.What is your name?

ICT619 10

Characteristics of a good agentAction• Agent must be able to take some action and not just provide

advice• Present state of web technology limits capability of Internet

agents • As the Internet becomes more agent-friendly, more capable

agents will emerge

Autonomy• An agent can be much more useful if it can act

autonomously• The right level of autonomy for a task must be found

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Characteristics of a good agent (cont.)

Communication• Must communicate well with the user• Should understand user’s goals, preferences and constraints• Useful communication requires shared knowledge on

– language of communication – problem domain

Example Problem: Web search engines• accept key words and phrases (some knowledge of the language) but • understand nothing about the documents they retrieve (no domain

knowledge)• Solution: provision of a machine-readable ontology

- a definition of a body of knowledge including its components and their relationships

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Characteristics of a good agent (cont.)

Adaptation• Can gain user confidence by learning user preferences• ML techniques such as ANNS and GA• Adapting to user preferences can be also achieved by using

data mining techniques such as clustering• Agent forms clusters of users with similar features• User's needs can then be anticipated by placing the user in

one of these clusters and analysing the cluster• Social problem solving method, similar to Amazon

recommendations

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Intelligent agents in E-Commerce (cont’d)

• In the need-identification stage, agents can help in purchases that are repetitive or predictable

• Continuously running agents can monitor a set of sensors or data streams and take actions when certain pre-specified conditions apply

• Agents can use rule-based systems or data mining techniques to discover patterns in customer behaviour to help customers find products

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Intelligent agents in E-commerce (cont.)

• In the merchant brokering stage, on-line shopping agents can look up prices for a chosen product for a number of merchants

• Many business-to-business transactions are canvassed

• In a web auction, customers are required to manage their own negotiation strategies

• Intelligent agents can help with this

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