Introduction

Expert System for Text Animation

An expert system is a computer system which mimics the behavior of an human expert in some specific subject area. The idea behind creating an expert system is that it can enable many people to benefit from the knowledge of one person - the expert. And not only will it make specialist knowledge more readily available, but also it may free the expert for the really difficult problems.

By providing it with a knowledge base for a certain subject area, ESTA can be used to create an expert system for that subject:

ESTA + Knowledge Base = Expert System

Each knowledge base contains rules for a specific domain. Thus, for a car fault diagnosis expert system the knowledge base will contain rules relating certain symptoms, such as excessive engine vibrations or lack of power at high speeds to possible causes. Similary, a knowledge base for an expert system to give taxadvice might contain rules relating marital status, mortgage commitments and age to the advisability (from the point of view of legally paying as little tax as possible) of taking out a newlife insurance policy, since these sometimes alter an individual's tax position beneficially. And likewise, given a plant classification knowledge base, an expert system could be built to recognize plants.

ESTA has all facilities to write the rules that will make up a knowledge base. Further, ESTA has an inference engine which can use the rules in the knowledge base to determine which advice is to be given to the expert system user or to initiate other actions. ESTA also features the ability for the expert system user to obtain answers to questions such as 'how' and 'why', etc.

The separation of the control and inference parts from the knowledge base is a fundamental feature of an expert system shell:

{bml intro.bmp}

ESTA is used by a knowledge engineer to create a knowledge base and by theexpert system user to consult a knowledge base.