Intelligent Agents

1.1 Introduction Computers are not very good at knowing what to do: every action a computer performs must be explicitly anticipated, planned for, and coded by a programmer. If a computer program ever encounters a situation that its designer did not anticipate, then the result is not usually pretty | a system crash at best, multiple loss of life at worst. This mundane fact is at the heart of our relationship with computers. It is so self-evident to the computer literate that it is rarely mentioned. And yet it comes as a complete surprise to those encountering computers for the rst time. For the most part, we are happy to accept computers as obedient, literal, unimaginative servants. For many applications (such as payroll processing), it is entirely acceptable. However, for an increasingly large number of applications, we require systems that can decide for themselves what they need to do in order to satisfy their design objectives. Such computer systems are known as agents. Agents that must operate robustly in rapidly changing, unpredictable, or open environments, where there is a signiicant possibility that actions can fail are known as intelligent agents, or sometimes autonomous agents. Here are examples of recent application areas for intelligent agents: When a space probe makes its long ight from Earth to the outer planets, a ground crew is usually required to continually track its progress, and decide how to deal with unexpected eventualities. This is costly and, if decisions are required quickly, it is simply not practicable. For these reasons, organisations like nasa are seriously investigating the possibility of making probes more autonomous | giving them richer decision making capability and responsibilities. Searching the Internet for the answer to a speciic query can be a long and tedious process. So, why not allow a computer program | an agent | do searches for us? The agent would typically be given a query that would require synthesising pieces of information from various diierent Internet information sources. Failure would occur when a particular resource was unavailable, (perhaps due to network failure), or where results could not be obtained. This chapter is about intelligent agents. Speciically, it aims to give you a thorough 2 Intelligent Agents introduction to the main issues associated with the design and implementation of intelligent agents. After reading it, I hope that you will understand: why agents are perceived to be an important new way …