EnrichingOWLwithInstanceRecognitionSemanticsfor

,20,of 20,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,6 November 2007,ONISW 2007, Auckland, New Zealand,Enriching OWL with Instance Recognition Semantics for Automated Semantic Annotation,Stephen W. Liddle,Information Systems Department,Yihong Ding & David W. Embley,Computer Science Department,Brigham Young University, Provo, Utah,Outline,Background,Instance recognition semantics,Automated semantic annotation,OWL-AA: OWL for Automated Annotation,Related work,Conclusion,Motivation,Big Hairy Audacious Goal:,deliver a machine-processable semantic web that will let us build agents to work intelligently on our behalf,Realistic Shorter-term Goal:,provide automatic semantic annotation machinery that turns ordinary web pages into semantic web pages by adding appropriate metadata,Goal of this Paper:,Show that we can extend OWL with epistemological declarations that let us use our data extraction engine to provide a solid automatic annotator that works with standard ontologies,Typical Approach,Typical approach to automatic annotation:,Use existing data extraction engine to wrap and annotate pages,BUT these approaches do not match extracted data with an ontology,Main drawback:,Post-processing step to map extracted data to the ontology,Our Approach,Our data extraction engine is ontology based and does not need a post-processing alignment step,We have demonstrated that our approach works (Ding/Embley/Liddle 2006, LNCS 4185),But our ontology language is not a W3C standard,OWL is a standard (W3C recommendation),But lacks sufficient declarative instance-recognition semantics for automatic annotation,A Solution,Extend OWL with declarative instance-recognition semantics,Call this OWL for Automated Annotation (OWL-AA),OWL-AA extension is epistemological in nature,Ontological definitions should be independent of the form of knowledge representation,Epistemological definitions may be sensitive to the form of knowledge representation,Our Contributions,OWL-AA extends OWL to provide for automated semantic annotation that,Embeds instance-recognition semantics declarations in ontologies and data extraction tools,Provides enhanced knowledge sharing and reuse via semantic web,Separates domain knowledge creation from semantic annotation process,Thus maintaining separation between concerns of domain experts and software developers,Instance Recognition Semantics,Instance Semantics Recognizers (ISRs),Formal specifications that identify instances of a concept in unstructured, semistructured, or structured text,Example:,Concept: PhoneNumber,Text: “Call me at 555-1212.”,ISR should recognize that 555-1212 in the text has the intensional meaning of PhoneNumber.,ISR Declarations in Data Frames,BedroomNr,internal representation:,Integer,external representation:,1-9|10,left context phrase:,b,right context phrase:,.*r(oo)?ms?,exception phrase:,s.*ba(th)?s?b.*r(oo)?ms?,context keywords:,b(r|d)s?|bdrms?|bed(rooms?)?,.,LessThan(p1: Price, p2: Price),returns,(Boolean),context keywords:,less than|or less|fewer| .,.,end,Feature,external representation:,ApartmentFeature.lexicon,.,end,Resiliency,There are no document layout dependencies in our ISR declarations,Other approaches typically use page layout information for extraction,Layout independence (resiliency) is a major benefit,Page layouts change periodically on the web,Different publishers in the same domain generally use different page layouts,Rewriting wrappers is costly,Annotation (Apartment Rental),Feature,External Representation,BedroomNr,External Representation,Context Phrase,BathNr,External Representation,Context Phrase,MonthRate,External Representation,Context Phrase,ContactPhone,External Representation,Context Keyword,CAPITOL HILL,Luxury 2 bdrm 2 bath, 2 grg, w/d, views,1700 sq ft. $1250 mo. Call 533-0293,ISR-Based Annotation Demo,http:/www.deg.byu.edu, demos section,extractionPattern,P,RDFS Graph of OWL-AA,ISR,ExternalRepresentation,ContextualRepresentation,subClassOf,subClassOf,domain,string,range,RegularExpression,ContextPhrase,LexiconList,subClassOf,subClassOf,ContextKeyword,subClassOf,subClassOf,LeftContextPhrase,RightContextPhrase,subClassOf,subClassOf,Exception,ISRvalue,P,subClassOf,domain,range,domain,owl:Class,range,range,range,range,domain,domain,domain,hasException,P,extractionRightContext,P,extractionKeyword,P,extractionLeftContext,P,OWL-AA Details (1),Add namespace,xmlns:owlaa=“http:/www.deg.byu.edu/OWL-AA#”,Add properties to OWL classes associating ISR declarations,OWL-AA Details (2),Declare ISR value and contextual restriction,1-9|10,OWL-AA Details (3),Add context phrases, context keywords, and exceptions,b,.,(see our paper for the rest of the details),OWL-AA Features,Syntactically, OWL-AA is attachment-independent w.r.t. OWL,No need to change a single line of existing OWL ontologies,Semantically, OWL-AA is also attachment- independent w.r.t. OWL,ISR declarations do not change meaning of existing ontology concepts at conceptual level,Prototype implementation translates OWL-AA to our own internal format for processing,Related Work,We arent the first to work on ISR declarations,IBMs Unstructured Information Management Architecture,There are many proposals for extending OWL,Two extensions related to ours,Context OWL (C-OWL),Extension for ontology mapping that localizes ontology content for global visibility,OWL-Eu,Extension that enriches OWL with customized datatypes, a significant need,Not attachment-independent, unfortunately,But our approach is compatible with OWL-Eu too,Conclusion,Automated semantic annotation is an important and fundamental problem for the semantic web,Key to automated annotation is ISR declaration,Our epistemological OWL-AA extension augments OWL to formalize ISR declarations,Conclusion (cont.),OWL-AA is fully compatible with ordinary OWL,Attachable/detachable,OWL-AA does not introduce complexity or decidability issues into OWL,Prototype implementation demonstrates that our approach works well,Embedding epistemological declarations in OWL is a fruitful area meriting further research,