Linked Services for the Web of Data
- 1. Towards The Next Wave Of Services Linked Services For The Web Of Data Dr. Carlos Pedrinaci Knowledge Media Institute - The Open University
- 2. Acknowledgements • J. Domingue, J. Kopecky, D. Liu, M. Maleshkova, H. Q. Yu, N. Li (OU) • Jose Manuel Gómez Pérez, Guillermo Alvaro (iSOCO) • Irene Celino (CEFRIEL) • SOA4All Project
- 3. Taken from the Introduction to Web Services by Oracle
- 4. Taken from the Introduction to Web Services by Oracle
- 5. What are the semantics of every service? ... and most importantly ... Where are they captured for being processed?
- 6. Excerpt of OWL-S Excerpt of WSMO Semantic Web SAWSDL, OWL-S and WSMO among others have been proposed Service Ontologies They have failed to gain adoption on the Web
- 7. Semantic Web Services • Predicated upon existing Web Services which are not prevalent on the Web • Complex to model • Complex to process • Hardly applicable • Missing data in ontological terms
- 8. Web Services have nothing to do with the Web
- 9. Number of Web Services found by Seekda.com in the last 52 Months ... but Verizon has about 1,500 Services Internally ...
- 10. Web APIs are the Widely used and reused Publicly available new WEB services With a real business model behind them Although harder automation!
- 13. Reality Check • Survey based on 220 Web APIs from ProgrammableWeb from 21 categories • Types of Web APIs – 45.5% REST, RPC 33.8%, Hybrid 20.7% • 40% of Web APIs do not state the used HTTP method! • Input and Output information – 72% do not state the data type of the input parameters – 61% use optional parameters, 45% use default values – 90% have as output XML, 42% JSON – 84% provide example request and 75% example response
- 14. Linked Services Exploiting the complementarity of Services and Linked Data
- 15. “Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/”
- 16. 256 Datasets 30+ Billion Triples Covering many diverse domains: - Media - Government - Geography - Life Sciences ... “Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/”
- 17. Linked Data Principles • Create a Web of Data by these 4 principles: • Use URIs as names for things • Use HTTP URIs so that people can look up those names. • When someone looks up a URI, provide useful information, using the standards (RDF*, SPARQL) • Include links to other URIs
- 18. Taken from Steve Bratt - W3C
- 19. How can Services help Linked Data?
- 20. Developing Applications The development of Linked Data Applications is more an art than an engineering discipline
- 21. Linked Services • Linked Services are services described as Linked Data (inputs, outputs, functionality...) • In other words, it is Linked Data describing reusable functionality • With supporting machinery Linked Services are Linked Data consumers and/or producers • Core building blocks for Linked Data Applications
- 22. 22
- 23. vi ce S er
- 24. Where can I find Linked Services?
- 25. Web of Documents Web of Data http://iserve.kmi.open.ac.uk
- 26. Web of Documents Web of Data http://iserve.kmi.open.ac.uk
- 27. Web of Documents Web of Data http://iserve.kmi.open.ac.uk
- 28. Web of Documents Web of Data http://iserve.kmi.open.ac.uk
- 29. “Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/”
- 30. “Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/”
- 33. How can I build a Linked Data application? What’s the benefit?
- 34. SOA4RE Mashes Linked Data and Web APIs Finds and Invokes Linked Services on the Fly Modularity and Extensibility as a core built-in feature
- 36. How can Linked Data help Services?
- 38. Issues with Services on the Web • Their semantics are unclear • The data they consume and produce is modelled in heterogeneous formats • They are not Web-ready • Their results are not globally identified • Their results are not de-referenceable
- 39. A typical Web API Pain HTML Not machine processable description Missing semantics
- 40. 36
- 41. 37
- 42. From Legacy Services to Linked Services • Services can be annotated using the Web of Data as background knowledge • This description makes the services • More accessible (semantics) • More applicable as they are expressed in terms of existing vocabularies used on the Web of Data
- 45. SOA4All Studio Combining distributed sources of data about services to better support the life- cycle of service-oriented applications
- 47. SWEET - MicroWSMO Editor Related Tooling SOA4All Studio
- 48. SWEET - MicroWSMO Editor Related Tooling SOWER - WSMO-Lite Editor Mashups Editor SOA4All Studio
- 49. SWEET - MicroWSMO Editor Related Tooling SOWER - WSMO-Lite Editor Mashups Editor SOA4All Studio SPICES - Invocation Interface
- 50. SWEET - MicroWSMO Editor Related Tooling SOWER - WSMO-Lite Editor Mashups Editor SOA4All Studio SPICES - Invocation Interface
- 51. ... and the entire Covering the entire life-cycle of service- based applications: infrastructure - Composition, Execution, etc
- 52. Reflections & Outlook
- 54. Reflections • Services need to be (in principle) commercially profitable for a public deployment • Trust and fault tolerance will be essential for their adoption • Current climate favours openness for creative collaborative innovation
- 55. Outlook • Service-orientation can provide the necessary engineering principles for advanced Linked Data Applications • Existing Linked Data and its principles may provide the necessary support for a Web-scale adoption of services • Service-orientation is subject to the network effect so ...
- 56. Put your piece in the puzzle
- 57. Thanks for your attention Interested on an Internship, PhD? Contact: [email protected]
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