Brought to you by EarthWeb
IT Library Logo

Click Here!
Click Here!

Search the site:
 
EXPERT SEARCH -----
Programming Languages
Databases
Security
Web Services
Network Services
Middleware
Components
Operating Systems
User Interfaces
Groupware & Collaboration
Content Management
Productivity Applications
Hardware
Fun & Games

EarthWeb Direct EarthWeb Direct Fatbrain Auctions Support Source Answers

EarthWeb sites
Crossnodes
Datamation
Developer.com
DICE
EarthWeb.com
EarthWeb Direct
ERP Hub
Gamelan
GoCertify.com
HTMLGoodies
Intranet Journal
IT Knowledge
IT Library
JavaGoodies
JARS
JavaScripts.com
open source IT
RoadCoders
Y2K Info

Previous Table of Contents Next


4.10. ASK THE BUYERS

The prior sections discussed some of the more important features to consider when choosing a shell. How important a specific feature is to a given application is also a point of consideration. One way to determine this is to ask expert system developers.

A survey of close to 300 developers was conducted, where each was given a list of shell features and asked to judge the importance of each feature based on a five-point scale, with 5 representing critical and 1 not important (Stylianou et al., 1995). The questionnaire also asked each developer to consider a specific problem-solving paradigm for which they have expert system design experience when evaluating shell features. Table 2 shows an adaption of part of the results from this survey. Several observations are notable.


TABLE 2
Survey Results of Importance of Shell Features
 
Control Design Diagnosis Monitoring Planning Prescription
Knowledge base
    Rules 4.0 4.1 3.7 2.6 4.0 4.3
    Rule sets 4.2 3.9 3.4 3.0 3.8 3.7
    Frames 3.3 3.8 2.9 3.1 3.7 2.5
    Induction 3.0 3.1 2.6 2.9 2.5 2.5
    Inexact reasoning 3.0 3.6 3.0 2.2 2.8 3.0
    Math processing 2.9 4.0 3.1 3.7 3.4 2.9
Inference
    Forward chaining 3.6 4.0 3.9 4.1 4.0 3.6
    Backward chaining 4.1 4.0 4.0 3.6 3.8 4.2
    Bidirectional chaining 3.3 3.9 3.2 3.5 3.8 3.1
    Nonmonotonic reasoning 3.3 3.7 3.0 3.9 3.6 3.0
Explanation facility
    Why and how 3.5 3.9 4.0 3.9 4.3 4.3
Developer interface
    Tracing 3.9 4.0 3.8 4.0 4.2 4.0
    Incremental compilation 2.7 3.2 2.8 3.4 3.2 3.1
    Knowledge browsing 3.7 3.5 3.2 3.4 3.7 3.5
    Customize user interface 3.4 3.8 4.2 3.6 4.0 4.4
    Open architecture 3.3 3.4 3.5 3.2 3.7 3.5
User interface
    Saved cases 3.1 3.5 3.3 3.9 3.0 3.5
    GUI 2.7 3.5 2.8 3.2 2.8 2.6
System interface
    Database link 3.5 4.3 3.9 4.0 4.0 4.0
    Software link 2.5 4.3 3.8 3.6 3.2 3.1
    Portability 3.5 4.1 3.7 3.8 3.9 3.9
    Embeddability 3.8 4.1 3.9 4.0 4.3 3.6
Support
    Documentation 3.8 4.0 4.0 3.7 4.1 4.1
    Example programs 3.0 3.5 3.2 3.5 3.3 3.5
    Help desk 2.8 3.7 3.4 3.5 3.5 4.0

Historically, most developed expert systems have been rule-based. According to the survey, rules continue to be the knowledge representation technique of choice. Though most shells offer a poor explanation facility, designers feel that this is an important feature to consider. Rule-tracing appears to be the most popular debugging tool. Being able to embed the developed system into an existing software environment and have the system exchange information with that software, particularly with a database, is favored.


Previous Table of Contents Next

footer nav
Use of this site is subject certain Terms & Conditions.
Copyright (c) 1996-1999 EarthWeb, Inc.. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of EarthWeb is prohibited. Please read our privacy policy for details.