A. Expert systems

An expert system is a computer system which is able to draw reasoned conclusions from a body of knowledge in a particular field, and communicate to the user the line of reasoning by which it has reached a conclusion.

Objectives of Expert Systems

The purpose of an expert system is to provide reasoned advice at a comparable level to that provided by a human expert. This capability has two main aims: to enhance the abilities of leading experts in certain fields, and to make a high level of expertise available to less highly qualified practitioners.

The first aim takes note of the fact that some areas of human expertise, such as the diagnosis and treatment of cancer, are so complex that even the leading experts can benefit from the systematic, logical approach provided by a computer. A computer system will take into consideration all the knowledge at its disposal in the consideration of every case, and will follow known lines of reasoning exhaustively, no matter how complex they are. These capabilities complement the skills of a human expert, which are generally based on a mixture of knowledge, experience, insight and intuition.

The second aim attempts to raise the level of skill of professionals who are not themselves leading experts. A large number of medical practitioners fall into this category, particularly in developing countries. When expert systems become widely available, the skills of these practitioners should be significantly enhanced.

In some expert systems, the expert knowledge is fixed into the system when it is constructed. In others, there is a built-in ability to learn from experience, including from mistakes made by the system.

Applications of Expert Systems

A small number of expert systems are in use at present. These are mainly in the following fields:

§ Medicine: Expert systems are in use for diagnosis and the planning of treatment in specialized fields. These include certain types of cancer, kidney diseases and some viral infections. Expert systems are also used to plan and monitor experiments, particularly in genetics. Expert systems for use by general practitioners in diagnosis and treatment are under investigation, but none are in widespread use at present.

§ Geological Prospecting: Expert systems have already proved their worth in oil prospecting, and are now being used for other minerals.

§ Designing Computer Configurations: Digital Equipment Corporation uses an expert system to design the computer configuration required when an order for a VAX minicomputer is placed. The expert system ensures that a compatible set of equipment is delivered, which meets the requirements of the customer.

§ Chemistry: The analysis of chemical structures from mass spectrometer data is often done with the aid of an expert system.

§ Legal Advice: Expert systems which give general legal advice, and assist in such matters as making Social Security claims, are at present under development.

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