Changes

'''Knowledge representation''' is an issue that arises in both [[cognitive science]] and [[artificial intelligence]]. In cognitive science it is concerned with how people store and process information. In

'''Knowledge representation''' is an issue that arises in both [[cognitive science]] and [[artificial intelligence]]. In cognitive science it is concerned with how people store and process information. In

artificial intelligence (AI) the primary aim is to store knowledge so that programs can process it and achieve the verisimilitude of human intelligence. AI researchers have borrowed representation theories from cognitive science.  Thus there are representation techniques such as frames, rules and  semantic networks which have originated from theories of human information processing. Since knowledge is used to achieve intelligent behavior, the fundamental goal of knowledge representation is to represent knowledge in a manner as to facilitate inferencing i.e. drawing conclusions from

artificial intelligence (AI) the primary aim is to store knowledge so that programs can process it and achieve the verisimilitude of human intelligence. AI researchers have borrowed representation theories from cognitive science.  Thus there are representation techniques such as frames, rules and  semantic networks which have originated from theories of human information processing. Since knowledge is used to achieve intelligent behavior, the fundamental goal of knowledge representation is to represent knowledge in a manner as to facilitate inferencing i.e. drawing conclusions from

Through such work, the difficulty of KR came to be better appreciated. In [[computational linguistics]], meanwhile, much larger databases of language information were being built, and these, along with great increases in computer speed and capacity, made deeper KR more feasible.

Through such work, the difficulty of KR came to be better appreciated. In [[computational linguistics]], meanwhile, much larger databases of language information were being built, and these, along with great increases in computer speed and capacity, made deeper KR more feasible.

Several [[programming languages]] have been developed that are oriented to KR. [[Prolog]] developed in 1972 (see http://www.aaai.org/AITopics/bbhist.html#mod), but popularized much later, represents propositions and basic logic, and can derive conclusions from known premises. [[KL-ONE]] (1980s) is more specifically aimed at knowledge representation itself.

Several [[programming languages]] have been developed that are oriented to KR. [[Prolog]] developed in 1972 (see https://www.aaai.org/AITopics/bbhist.html#mod), but popularized much later, represents propositions and basic logic, and can derive conclusions from known premises. [[KL-ONE]] (1980s) is more specifically aimed at knowledge representation itself.

In the electronic document world, languages were being developed to represent the structure of documents more explicitly, such as [[SGML]] and later [[XML]]. These facilitated [[information retrieval]] and [[data mining]] efforts, which have in recent years begun to relate to KR. The Web community is now especially interested in the [[Semantic Web]], in which XML-based KR languages such as [[Resource Description Framework|RDF]], [[Topic Maps]], and others can be used to make KR information available to Web systems.

In the electronic document world, languages were being developed to represent the structure of documents more explicitly, such as [[SGML]] and later [[XML]]. These facilitated [[information retrieval]] and [[data mining]] efforts, which have in recent years begun to relate to KR. The Web community is now especially interested in the [[Semantic Web]], in which XML-based KR languages such as [[Resource Description Framework|RDF]], [[Topic Maps]], and others can be used to make KR information available to Web systems.

While [[hyperlink]]s have come into widespread use, the closely related [[semantic link]] is not yet widely used. The [[mathematical table]] has been used since [[Babylon]]ian times. More recently, these tables have been used to represent the outcomes of logic operations, such as [[truth table]]s, which were used to study and model Boolean logic, for example. [[Spreadsheet]]s are yet another tabular representation of knowledge. Other knowledge representations are [[tree structure|trees]], by means of which the connections among fundamental concepts and derivative concepts can be shown.  

While [[hyperlink]]s have come into widespread use, the closely related [[semantic link]] is not yet widely used. The [[mathematical table]] has been used since [[Babylon]]ian times. More recently, these tables have been used to represent the outcomes of logic operations, such as [[truth table]]s, which were used to study and model Boolean logic, for example. [[Spreadsheet]]s are yet another tabular representation of knowledge. Other knowledge representations are [[tree structure|trees]], by means of which the connections among fundamental concepts and derivative concepts can be shown.  

Visual representations, called a [[TheBrain Technologies Corp.|"plex" as developed by TheBrain Technologies]] are relatively new in the field of knowledge management but give the user a way to visualise how one thought or idea is connected to other ideas enabling the possibility of moving from one thought to another in order to locate required information. The approach is not without its competitors. Other visual search tools are built by [http://www.convera.com/ Convera Corporation], [http://www.kmconnection.com/pguide/KSP2000348.htm Entopia, Inc.], [http://www.epeople.com/home.shtml EPeople Inc.], and [http://www.inxight.com/ Inxight Software Inc].

Visual representations, called a [[TheBrain Technologies Corp.|"plex" as developed by TheBrain Technologies]] are relatively new in the field of knowledge management but give the user a way to visualise how one thought or idea is connected to other ideas enabling the possibility of moving from one thought to another in order to locate required information. The approach is not without its competitors. Other visual search tools are built by [https://www.convera.com/ Convera Corporation], [https://www.kmconnection.com/pguide/KSP2000348.htm Entopia, Inc.], [https://www.epeople.com/home.shtml EPeople Inc.], and [https://www.inxight.com/ Inxight Software Inc].

==Storage and manipulation==

==Storage and manipulation==

Using frames for [[expert systems]] is an application of [[object-oriented]] programming, with [[inheritance]] of features described by the "[[is-a]]" link. However, there has been no small amount of [[inconsistency]] in the usage of the "is-a" link: [[Ronald J. Brachman]] wrote a paper titled "What IS-A is and isn't", wherein 29 different semantics were found in projects whose knowledge representation schemes involved an "is-a" link. Other links include the "[[has-part]]" link.  

Using frames for [[expert systems]] is an application of [[object-oriented]] programming, with [[inheritance]] of features described by the "[[is-a]]" link. However, there has been no small amount of [[inconsistency]] in the usage of the "is-a" link: [[Ronald J. Brachman]] wrote a paper titled "What IS-A is and isn't", wherein 29 different semantics were found in projects whose knowledge representation schemes involved an "is-a" link. Other links include the "[[has-part]]" link.  

Frame structures are well-suited for the representation of schematic knowledge and stereotypical cognitive patterns. The elements of such schematic patterns are weighted unequally, attributing higher weights to the more typical elements of a  [http://moodle.ed.uiuc.edu/wiked/index.php/Schemas schema]. A pattern is activated by certain expectations: If a person sees a big bird, he or she will classify it rather as a sea eagle than a golden eagle, assuming that his or her "sea-scheme" is currently activated and his "land-scheme" is not.

Frame structures are well-suited for the representation of schematic knowledge and stereotypical cognitive patterns. The elements of such schematic patterns are weighted unequally, attributing higher weights to the more typical elements of a  [https://moodle.ed.uiuc.edu/wiked/index.php/Schemas schema]. A pattern is activated by certain expectations: If a person sees a big bird, he or she will classify it rather as a sea eagle than a golden eagle, assuming that his or her "sea-scheme" is currently activated and his "land-scheme" is not.

Frame representations are object-centered in the same sense as  [[semantic network]]s are: All the facts and properties connected with a concept are located in one place - there is no need for costly search processes in the database.

Frame representations are object-centered in the same sense as  [[semantic network]]s are: All the facts and properties connected with a concept are located in one place - there is no need for costly search processes in the database.

Examples of notations:

Examples of notations:

* [[DATR]] is an example for representing [[Lexicon|lexical]] knowledge  

* [[DATR]] is an example for representing [[Lexicon|lexical]] knowledge  

* [[Resource Description Framework|RDF]] is a simple [[notation]] for representing relationships between and among [[object (philosophy)|object]]s

* [[Resource Description Framework|RDF]] is a simple [[notation]] for representing relationships between and among [[object (philosophy)|object]]s[

 

https://en.wikipedia.org/wiki/Knowledge_representation

* [[LoomLanguage|Loom]]

* [[KM programming language|KM]] : the Knowledge Machine ([[Frame language|frame]]-based language used for knowledge representation work)

 

==References==

==References==

* Amaravadi, C. S., “Knowledge Management for Administrative Knowledge,” Expert Systems, 25(2), pp 53-61, May 2005.

* Amaravadi, C. S., “Knowledge Management for Administrative Knowledge,” Expert Systems, 25(2), pp 53-61, May 2005.

* [[Ronald J. Brachman]]; What IS-A is and isn't. An Analysis of Taxonomic Links in Semantic Networks; IEEE Computer, 16 (10); October 1983 [http://citeseer.nj.nec.com/context/177306/0]

* [[Ronald J. Brachman]]; What IS-A is and isn't. An Analysis of Taxonomic Links in Semantic Networks; IEEE Computer, 16 (10); October 1983 [https://citeseer.nj.nec.com/context/177306/0]

* Jean-Luc Hainaut, Jean-Marc Hick, Vincent Englebert, Jean Henrard, Didier Roland: Understanding Implementations of IS-A Relations. ER 1996: 42-57 [http://www.informatik.uni-trier.de/~ley/db/conf/er/HainautHEHR96.html]

* Jean-Luc Hainaut, Jean-Marc Hick, Vincent Englebert, Jean Henrard, Didier Roland: Understanding Implementations of IS-A Relations. ER 1996: 42-57 [https://www.informatik.uni-trier.de/~ley/db/conf/er/HainautHEHR96.html]

* Hermann Helbig: ''Knowledge Representation and the Semantics of Natural Language'', Springer, Berlin, Heidelberg, New York 2006

* Hermann Helbig: ''Knowledge Representation and the Semantics of Natural Language'', Springer, Berlin, Heidelberg, New York 2006

* Arthur B. Markman: ''Knowledge Representation''  Lawrence Erlbaum Associates, 1998

* Arthur B. Markman: ''Knowledge Representation''  Lawrence Erlbaum Associates, 1998

==External links==

==External links==

* [http://medg.lcs.mit.edu/ftp/psz/k-rep.html What is a Knowledge Representation?] by Randall Davis and others

* [https://medg.lcs.mit.edu/ftp/psz/k-rep.html What is a Knowledge Representation?] by Randall Davis and others

* [http://www.makhfi.com/KCM_intro.htm Introduction to Knowledge Modeling] by Pejman Makhfi

* [https://www.makhfi.com/KCM_intro.htm Introduction to Knowledge Modeling] by Pejman Makhfi

* [http://www.inf.unibz.it/~franconi/dl/course/ Introduction to Description Logics course] by Enrico Franconi, Faculty of Computer Science, Free University of Bolzano, Italy  

* [https://www.inf.unibz.it/~franconi/dl/course/ Introduction to Description Logics course] by Enrico Franconi, Faculty of Computer Science, Free University of Bolzano, Italy  

* [http://www.ccl.kuleuven.ac.be/LKR/html/datr.html DATR Lexical knowledge representation language]

* [https://www.ccl.kuleuven.ac.be/LKR/html/datr.html DATR Lexical knowledge representation language]

* [http://www.isi.edu/isd/LOOM/LOOM-HOME.html Loom Project Home Page]

* [https://www.isi.edu/isd/LOOM/LOOM-HOME.html Loom Project Home Page]

* [http://www.research.att.com/sw/tools/classic/tm/ijcai-95-with-scenario.html Description Logic in Practice: A CLASSIC Application]

* [https://www.research.att.com/sw/tools/classic/tm/ijcai-95-with-scenario.html Description Logic in Practice: A CLASSIC Application]

* [http://www.dfki.uni-kl.de/ruleml/ The Rule Markup Initiative]

* [https://www.dfki.uni-kl.de/ruleml/ The Rule Markup Initiative]

* [http://moodle.ed.uiuc.edu/wiked/index.php/Schemas Schemas]

* [https://moodle.ed.uiuc.edu/wiked/index.php/Schemas Schemas]

* [http://nelements.org Nelements KOS] - a generic 3d knowledge representation system

* [https://nelements.org Nelements KOS] - a generic 3d knowledge representation system

 

[[Category: General Reference]]

[[Category: General Reference]]