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Language Technologies and the Semantic Web: An Essential Relationship.

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Presentation on theme: "Language Technologies and the Semantic Web: An Essential Relationship."— Presentation transcript:

1 Language Technologies and the Semantic Web: An Essential Relationship.
Enrico Motta Professor of Knowledge Technologies Knowledge Media Institute The Open University

2 Update on the Semantic Web
Content of the Talk Update on the Semantic Web Beyond the hype What it is Why it is interesting What’s its status? Semantic Web and AI Semantic Web Applications Key features Reasoning on the Semantic Web Key role of Language Technologies Conclusions

3 The Semantic Web in 2 minutes…

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6 <foaf:Person rdf:about="http://identifiers. kmi. open. ac
<foaf:name>Enrico Motta</foaf:name> <foaf:firstName>Enrico</foaf:firstName> <foaf:surname>Motta</foaf:surname> <foaf:phone rdf:resource="tel:+44-(0) "/> <foaf:homepage rdf:resource=" <foaf:workplaceHomepage rdf:resource=" <foaf:depiction rdf:resource=" <foaf:topic_interest>Knowledge Technologies</foaf:topic_interest> <foaf:topic_interest>Semantic Web</foaf:topic_interest> <foaf:topic_interest>Ontologies</foaf:topic_interest> <foaf:topic_interest>Problem Solving Methods</foaf:topic_interest> <foaf:topic_interest>Knowledge Modelling</foaf:topic_interest> <foaf:topic_interest>Knowledge Management</foaf:topic_interest> <foaf:based_near> <geo:Point> <geo:lat> </geo:lat> <geo:long> </geo:long> <contact:nearestAirport> <airport:name>London Luton Airport</airport:name> <airport:iataCode>LTN</airport:iataCode> <airport:location>Luton, United Kingdom</airport:location> <geo:lat> </geo:lat> <geo:long> </geo:long> <rdfs:seeAlso rdf:resource=" <foaf:currentProject> <foaf:Project> <foaf:name>AquaLog</foaf:name> </foaf:currentProject>

7 The foaf ontology

8 The SW as ‘Web of Data’

9 Current status of the semantic web
10-20 million semantic web documents Expressed in RDF, OWL, DAML+OIL 7K-10K ontologies These cover a variety of domains - multimedia, computing, management, bio-medical sciences, geography, entertainment, upper level concepts, etc… The above figures refer to resources which are publicly accessible on the web

10 The Semantic Web today To a significant extent the Semantic Web is already in place and is characterized by a widespread production of formalized knowledge models (ontologies and metadata), from a variety of different groups and individuals “The Next Knowledge Medium - An information network with semi-automated services for the generation, distribution, and consumption of knowledge” Stefik, 1986 “Knowledge modelling to become a new form of literacy?” Stutt and Motta, 1997 Still primarily a research enterprise, however interest is rapidly increasing in both governmental and business organizations “early adopters” phase The result is slowly emerging as an unprecedented knowledge resource, which can enable a new generation of intelligent applications on the web

11 Semantic Web Applications
What can you do with the Semantic Web?

12 “Corporate Semantic Webs”
A ‘corporate ontology’ is used to provide a homogeneous view over heterogeneous data sources Often tackle Enterprise Information Integration scenarios Hailed by Gartner as one of the key emerging strategic technology trends E.g., see personal information management in Garlik

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14 Exploiting large scale semantics
Next Generation SW Applications Semantic Web Semantic Web Gateway

15 Exploiting large scale semantics
Next Generation SW Applications Semantic Web

16 NGSW Applications in the context of AI research

17 Knowledge-Based Systems
“Today there has been a shift in paradigm. The fundamental problem of understanding intelligence is not the identification of a few powerful techniques, but rather the question of how to represent large amounts of knowledge in a fashion that permits their effective use” Goldstein and Papert, 1977 Large Body of Knowledge Intelligent Behaviour

18 The Knowledge Acquisition Bottleneck
Large Body of Knowledge KA Bottleneck Intelligent Behaviour

19 SW as Enabler of Intelligent Behaviour
Both a platform for knowledge publishing and a large scale source of knowledge Intelligent Behaviour

20 KBS vs SW Systems Classic KBS SW Systems Provenance Centralized
Distributed Size Small/Medium Extra Huge Repr. Schema Homogeneous Heterogeneous Quality High Very Variable Degree of trust

21 Key Paradigm Shift Classic KBS SW Systems Intelligent Behaviour A function of sophisticated, logical, task-centric problem solving A side-effect of being able to integrate different types of reasoning to handle size and heterogeneous quality and representation

22 Next Generation SW Applications: Examples
Case Study 1: Automatic Alignment of Thesauri in the Agricultural/Fishery Domain

23 SCARLET - matching by Harvesting the SW
Method SCARLET - matching by Harvesting the SW Automatically select and combine multiple online ontologies to derive a relation Access Semantic Web Scarlet Deduce Concept_A (e.g., Supermarket) Concept_B (e.g., Building) Semantic Relation ( )

24 Two strategies Scarlet Scarlet Supermarket Building Cholesterol
OrganicChemical PublicBuilding Lipid Shop Steroid Steroid Supermarket Cholesterol Semantic Web Scarlet Scarlet Supermarket Building Cholesterol OrganicChemical (A) (B) Deriving relations from (A) one ontology and (B) across ontologies.

25 Experiment Matching: AGROVOC UN’s Food and Agriculture
Organisation (FAO) thesaurus descriptor terms non-descriptor terms NALT US National Agricultural Library Thesaurus descriptor terms non-descriptor terms

26 226 Used Ontologies http://139.91.183.30:9090/RDF/VRP/Examples/tap.rdf
htechsight/Technologies.daml

27 Evaluation 1 - Precision
Manual assessment of 1000 mappings (15%) Evaluators: Researchers in the area of the Semantic Web 6 people split in two groups Results: Comparable to best results for background knowledge based matchers.

28 Evaluation 2 – Error Analysis

29 Other Case Studies…

30 Giving meaning to tags

31 Example Cluster_1: {college commerce corporate course education high instructing learn learning lms school student} education training1,4 qualification corporate1 institution university2,3 college2 postSecondary School2 school2 student3 studiesAt course3 offersCourse takesCourse activities4 learning4 teaching4 1http://gate.ac.uk/projects/htechsight/Employment.daml. 2http://reliant.teknowledge.com/DAML/Mid-level-ontology.daml. 3http:// 4http://

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35 Conclusions

36 Typical misconceptions…
“The SW is a long-term vision…” Ehm…actually… it already exists… “The SW will never work because nobody is going to annotate their web pages” The SW is not about annotating web pages, the SW is a web of data, most of which are generated from DBs, or from web mining software, or from applications which produce SW data as a side effect of supporting users’ tasks “The idea of a universal ontology has failed before and will fail again. Hence the SW is doomed” The SW is not about a single universal ontology. Already there are around 10K ontologies and the number is growing… SW applications may use 1, 2, 3, or even hundreds of ontologies.

37 SW and Language Technologies
All the applications mentioned here combine language, web, statistical and semantic technologies Heterogeneity and sloppy modelling implies that language and statistical technologies are almost always needed when building NGSW apps In contrast with traditional KBS, intelligent behaviour is more a side-effect of intg. multiple techniques to handle scale and heterogeneity, rather than a function of powerful deductive reasoning

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