Page 32 - DCAP310_INTRODUCTION_TO_ARTIFICIAL_INTELLIGENCE_AND_EXPERT_SYSTEMS

Introduction to Artificial Intelligence & Expert Systems

Notes The following are the different stages in the development of KBS:
Identification
Conceptualization

Formalization
Implementation

2.3.4 Testing

Testing is the process in which the knowledge-base systems are checked. Following are the
phases in the testing process:
Identification: In this phase, Knowledge Engineer and Domain Expert work together closely to
describe the problem that the KBS expected to solve. Such interactive procedure is typical of the
entire KBS development process. Additional resources, such as other experts and knowledge
engineers and reference journals are also identified in the identification stage.
Conceptualization: This stage involves analyzing the problem. Knowledge Engineer represents
graphical representation of the relationship between the objects and the process in the problem
domain. The problem is decomposed in to sub-problems and their interrelationships are properly
conceptualized. Then the identification stage is revised again. Such interactive process can occur
in any stage of development.

Formalization: Both identification and conceptualization are concerned on understanding the
problem. The process of formalization means that the problem is connected to its KBS, by
analyzing the relation mentioned in conceptualization. Knowledge Engineer selects the
development techniques that are appropriate to required KBS. It must be familiar with different
types of AI techniques, i.e. heuristic search techniques and knowledge representation mechanisms
that are used in the development of KBS.
Implementation: During the implementation stage of KBS, Knowledge Engineer determines
whether correct techniques were chosen or not. Otherwise the knowledge engineer has tore
formalize the concepts or use new development tools.
Testing: Testing provides an opportunity to the knowledge engineer to identify the strengths
and weaknesses of the system that will lead to identify and see whether any modifications are
required.
This structure of Expert Systems is most closely matched by the structure of logical programming
(its computational model). In a logic programming language such as LISP and PROLOG, PROLOG
statements are relations of a restricted form called “Clauses” and the execution of such program
is a suitably controlled logic deduction from the Clauses forming the program. A Clause is a
well formed Formula consisting of Conjunction and Disjunction of Literals.
The following logic program for family has three Conditions of four Clauses:
Father (Bill, John)

Father (John, Tom)
Grandfather (X, Z): father (X, Y), mother (Y, Z)
Grandfather (X, Z): father (X, Y), father (Y, Z)
The first two clauses define that Bill is the father of John, second two clauses use the variables X,
Y and Z to represent (express) the rule that if X is the grandfather of Z, if X is the father of Y and

26 LOVELY PROFESSIONAL UNIVERSITY