![]() |
|||
![]()
|
![]() |
![]() |
![]() |
11.2. KNOWLEDGE ACQUISITIONIt is important to bear in mind that knowledge acquisition is an independent phase in the ontology development process. However, it is coincident with other phases. As stated previously, most of the acquisition is done simultaneously with the requirements specification phase, and decreases as the ontology development process moves forward. Experts, books, handbooks, figures, tables, and even other ontologies are sources of knowledge from which the knowledge can be elicited, and acquired, and used in conjunction with techniques such as: brainstorming, interviews, questionnaires, formal and informal texts analysis, knowledge acquisition tools, etc. For example, if you have no clear idea of the purpose of your ontology, the brainstorming technique, informal interviews with experts, and examination of similar ontologies will allow you to elaborate a preliminary glossary with terms that are potentially relevant. To refine the list of terms and their meanings, formal and informal texts, analysis techniques in books and handbooks, combined with structured and nonstructured interviews with experts might be used to include or remove terms in the glossary. Interviews with experts might help you build concepts classification trees and compare them with figures given in books. 11.3. CONCEPTUALIZATIONIn this phase, METHONTOLOGY proposes to structure the domain knowledge in a conceptual model (a noncomputable representation of the world) that describes the domain in terms of the domain vocabulary identified in the ontology specification phase. The first thing to do is to build a complete Glossary of Terms (GT) as shown in Table 1. Terms include concepts, instances, verbs, and properties. So, the GT identifies and gathers all the useful and potentially usable domain knowledge and its meanings. Note that you do not start from scratch when you develop your GT. If you have drawn up a good requirements specification document, many terms will have been identified in that document. Others will be identified as the ontology construction process advances. Then, these new terms must be included in the GT. Once you have almost completed the GT, you need to group terms as concepts and verbs. Each set of concepts/verbs would include concepts/verbs that are closely related to other concepts/verbs inside the same group as opposed to other groups. Indeed, for each set of related concepts and related verbs, a concepts classification tree and a verbs diagram is built. Figures 9 and 10 show a concepts classification tree and a verbs diagram, respectively, in the domain of chemicals. After they have been built, you can split your ontology development process into different, but related, development teams. Figure 11 graphically summarizes the intermediate representations used in the conceptualization phase.
|
![]() |
|
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. |