Knowledge Representation ( English : knowledge representation ) is used in the context of knowledge modeling to knowledge in knowledge-based systems to map formal. Various formal languages and notations have been proposed for this purpose. A collection of knowledge represented in this way is called a knowledge base or knowledge base; Formalized knowledge is stored in a distributed manner in the Semantic Web . In contrast to knowledge representation, the focus in knowledge organization is more on the order of existing knowledge that is not represented by itself, but rather described by metadata .
The methods of knowledge representation are used, among other things, in the construction of expert systems , machine translation programs , systems for computer-aided maintenance and database query programs.
Knowledge Representation Techniques
There are different systems for the order and representation of knowledge. In roughly ascending order according to their thickness, these are:
- Catalog , glossary , taxonomy (simple controlled vocabularies ),
- Classification , thesaurus (limited number of relations usually without inheritance relation),
- Semantic network , ontology , frames , production rules ,
- Axiom system , predicate logic as well
- multilayer extended semantic networks ( MultiNet ).
The last-mentioned MultiNet paradigm serves as the basis for a semantics-oriented language technology that is also used commercially . If no formal representation is available or possible, other methods must be found to convey this, for example from the area of information visualization .
Criteria for the quality of representation
Important criteria for choosing a knowledge representation system are:
- How are correct syntax and correct semantics ensured?
- Adequacy / expressivity / power
- Does the language represent the required ontology components clearly and flexibly enough?
- How efficiently can you infer?
- How steep is the learning curve for mapping and querying knowledge?
- Can be translated into other syntax formats or languages
- R. J. Brachman, H. J. Levesque: Readings in Knowledge Representation . Morgan Kaufmann, Los Altos 1985.
- John F. Sowa : Knowledge Representation. Logical, Philosophical, and Computational Foundations . Brooks Cole Publishing, 1999. ISBN 0-534-94965-7 .
- R. J. Brachman, H. J. Levesque: Knowledge Representation and Reasoning . Morgan Kaufmann, 2004.
- Hermann Helbig : Knowledge Representation and the Semantics of Natural Language . Springer, Berlin / Heidelberg / New York, 2006.
- Wolfgang G. Stock , Mechtild Stock: Knowledge representation . Oldenbourg, Munich 2008. ISBN 978-3-486-58439-4 .
- Computing a theory of all knowledge - TED Talk by Stephen Wolfram about the representation and mathematical modeling of knowledge.
-  GI website for the # KI50 campaign. Retrieved August 26, 2019.