Information Technology Reference
In-Depth Information
Table 9.1. Characterizing operationality assessment
System
Variability
Granularity
Certainty
GENESIS
Dynamic
Binary
No guarantee
LEX2
Dynamic
Binary
No guarantee
SOAR
Dynamic
Binary
No guarantee
PRODIGY
Static
Continual
No guarantee
Meta-LEX
Dynamic
Continual
Guarantee
A model of EBL can be established based upon the above space description.
The EBL system mainly comprises of perform system PS, learning system EXL,
and domain knowledge base KB (set of rule transformation of various
descriptions). Let concept space be C, concept description space be CD and
example space be I, the working process of the system is as follows: The input of
EXL is description D
1
(usually inoperable) of concept C
1
, description
transformation of D
1
is pursued (this is a searching process) based on knowledge
in KB. PS tests every transformed result, the learning process is over and D
2
is
outputted until PS gets an operable description D
2
. The model is illustrated in
figure 9.2.
N
Conversion of
concept
description
Y
Is the result
operable?
D
2
D
1
EXL
KB
PS
Figure 9.2. Model of EBL
9.3 Explanation-Based Generalization
9.3.1
Basic principle
In 1986 Mitchell, Keller and Kedar-Cabelli put forward a unified framework of
explanation based generalization (abbreviated as EBG). The basic principle is to
