Linked Data Overview - AGI Technical SIG

1,536 views
1,438 views

Published on

An overview of Linked Data (from an outsider's point of view!). Given at AGI Technical SIG event on 22nd November 2011

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,536
On SlideShare
0
From Embeds
0
Number of Embeds
567
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Linked Data Overview - AGI Technical SIG

  1. 1. Linked Data – An Overview Chris Ewing 22 nd November 2011 http://www.flickr.com/photos/reedsturtevant/4288406572/sizes/l/in/set-72157623118237295/
  2. 2. Summary <ul><li>What is Linked Data? </li></ul><ul><li>Why is it useful? </li></ul><ul><li>Geo Examples </li></ul>http://www.w3.org/DesignIssues/diagrams/lod/480759174v0_350x350_Back.jpg
  3. 3. What is Linked Data? <ul><li>A method of publishing structured data so that it can be interlinked and become more useful </li></ul><ul><li>Builds upon existing web technologies (HTTP, URI) </li></ul>
  4. 4. The semantic web <ul><li>Linked Data is part of the semantic web (also nicknamed the Giant Global Graph (GGG)) </li></ul><ul><li>Semantic Web describes: </li></ul><ul><ul><li>Relationships between things </li></ul></ul><ul><ul><li>Properties of things </li></ul></ul>http://upload.wikimedia.org/wikipedia/en/3/37/Semantic-web-stack.png The Semantic Web Stack
  5. 5. Linked Data - Timeline <ul><li>Basics have been around since birth of internet </li></ul><ul><li>Tim Berners-Lee paper in 2006 </li></ul><ul><li>TED talk by TB-L in 2009 </li></ul><ul><li>TB-L appointed UK Gov advisor to opening up Government data – Spring 2009 </li></ul><ul><li>Data.gov.uk launches 2010 </li></ul><ul><li>UK Location Linked Data workshop – Sep 2010 </li></ul><ul><li>This workshop today! </li></ul>
  6. 6. Why is it useful? <ul><li>Linked Data allows you to discover, connect to, describe, and re-use all kinds of data </li></ul><ul><li>Better answers to searches etc. </li></ul>http://rww.readwriteweb.netdna-cdn.com/images/linked_data_graph.jpg
  7. 7. Why is it useful? <ul><li>Can combine ALL kinds of data in a similar environment , share ACROSS organisations & reuse data and links </li></ul><ul><li>Faster access to data </li></ul><ul><li>More relevant data returned </li></ul>
  8. 8. Linked Data - Rules <ul><li>Rule 1 – put something on the web </li></ul><ul><ul><li>Not just docs, but people, places too </li></ul></ul><ul><li>Rule 2 – get information back </li></ul><ul><ul><li>Data in a useful format </li></ul></ul><ul><li>Rule 3 – data is relationships </li></ul><ul><ul><li>e.g. I was born in Liverpool, Liverpool is in Merseyside </li></ul></ul>
  9. 9. Rule 1 - on the web <ul><li>In the beginning only documents on the web </li></ul><ul><li>Now also music, video, maps, people, places etc. </li></ul>
  10. 10. Rule 2 – get information back <ul><li>Ask a question and get a useful response </li></ul><ul><li>Show me all railways from OS 50k gazetteer </li></ul>1. Search 2. Results 3. Items
  11. 11.
  12. 12.
  13. 13.
  14. 14. Rule 3 – Data is Relationships <ul><li>Postcode SO16 4GU is within SO16 4 </li></ul><ul><li>SO16 4 is within SO16 </li></ul><ul><li>SO16 is within SO </li></ul><ul><li>SO is within City of Southampton </li></ul><ul><li>Etc. </li></ul>
  15. 15. Linked Data “Rating” 2010 -http://www.w3.org/DesignIssues/LinkedData.html ★ Available on the web (whatever format), but with an open licence ★★ Available as machine-readable structured data (e.g. excel instead of image scan of a table) ★★★ as (2) plus non-proprietary format (e.g. CSV instead of excel) ★★★★ All the above plus, Use open standards from W3C (RDF and SPARQL) to identify things, so that people can point at your stuff ★★★★★ All the above, plus: Link your data to other people’s data to provide context
  16. 16. Linked Data Acronyms http://www.clir.org/pubs/archives/linked-data-survey/part00_b_acronyms.html
  17. 17. URI <ul><li>Uniform Resource Identifier </li></ul><ul><li>String of characters used to reference a name or a resource on the Internet </li></ul><ul><li>Names for things! </li></ul><ul><li>http://example.org/absolute/URI/with/absolute/path/to/resource.txt </li></ul><ul><li>//example.org/scheme-relative/URI/with/absolute/path/to/resource.txt </li></ul><ul><li>relative/path/to/resource.txt </li></ul><ul><li>../../../resource.txt </li></ul><ul><li>./resource.txt#frag01 </li></ul><ul><li>resource.txt </li></ul><ul><li>#frag01 </li></ul>
  18. 18. RDF <ul><li>Resource Description Framework </li></ul><ul><li>RDF uses URI references to identify resources and properties </li></ul><ul><li>“ The sky has the colour blue&quot; in RDF is as the triple: </li></ul><ul><ul><li>a subject denoting &quot;the sky&quot; </li></ul></ul><ul><ul><li>a predicate denoting &quot;has the colour&quot; </li></ul></ul><ul><ul><li>an object denoting &quot;blue“ </li></ul></ul>* http://www.w3.org/TR/rdf-concepts/#section-SimpleFacts RDF Triple
  19. 19. OWL <ul><li>OWL Web Ontology Language </li></ul><ul><li>describes the meaning of terminology in web documents </li></ul>http://www.w3.org/TR/owl-features/
  20. 20. SPARQL <ul><li>SPARQL - SPARQL Protocol and RDF Query Language </li></ul><ul><li>Query the resources </li></ul><ul><li>PREFIX foaf: <http://xmlns.com/foaf/0.1/> </li></ul><ul><li>SELECT ?name ?email </li></ul><ul><li>WHERE { </li></ul><ul><li>?person a foaf:Person. </li></ul><ul><li>?person foaf:name ?name. </li></ul><ul><li>?person foaf:mbox ?email. </li></ul><ul><li>} </li></ul>e.g. Returns Name and Email of everyone in a dataset
  21. 21. GeoSPARQL <ul><li>Geospatial version of SPARQL </li></ul><ul><li>Created by an OGC working group </li></ul><ul><li>Goal is to “ support representing and querying geospatial data on the Semantic Web ” </li></ul><ul><li>Standardisation vote at end of 2011 </li></ul><ul><li>Example – Select Airports near London </li></ul>
  22. 22. Some examples <ul><li>GeoNames </li></ul><ul><li>Data.gov.uk </li></ul><ul><li>Ordnance Survey </li></ul><ul><li>DNF </li></ul><ul><li>INSPIRE </li></ul><ul><li>UK Location </li></ul>
  23. 23. GeoNames <ul><li>makes it possible to add geospatial semantic information to the Word Wide Web. </li></ul><ul><li>Features in the GeoNames Semantic Web are interlinked with each other </li></ul><ul><li>All starts with Mother Earth </li></ul><ul><li>RDF dump with 7857409 features with 145919822 RDF triples (2011 08 24) </li></ul>
  24. 24. Data.gov.uk <ul><li>http://data.gov.uk/linked-data </li></ul><ul><li>A series of SPARQL end points let you query the different data sources </li></ul>
  25. 25. Ordnance Survey Linked Data <ul><li>http://data.ordnancesurvey.co.uk/.html </li></ul><ul><li>3 Linked Data datasets so far: </li></ul><ul><ul><li>Postcodes </li></ul></ul><ul><ul><li>50k Gazeetter </li></ul></ul><ul><ul><li>Administrative boundaries </li></ul></ul><ul><li>Free Text Search - http://api.talis.com/stores/ordnance-survey/items </li></ul>
  26. 26. DNF / UK Location <ul><li>Digital National Framework </li></ul><ul><li>Oct 2011 – new Linked Data subgroup at BCS </li></ul><ul><li>EA bathing waters example from BSI Geographic Standards Committee* </li></ul><ul><li>UKLocation / BCS Linked Data business benefits – this Thursday 24 th Nov at BCS offices </li></ul>*http://www.agi.org.uk/storage/GeoCommunity/AGI2011/Presentations/RichardDuffield.pdf
  27. 27. *http://www.agi.org.uk/storage/GeoCommunity/AGI2011/Presentations/RichardDuffield.pdf
  28. 28. INSPIRE and Linked Data *http://inspire.jrc.ec.europa.eu/documents/Network_Services/Linked_Data_&_INSPIRE_v101.pdf
  29. 29. http://www.flickr.com/photos/fenng/3199355352/sizes/o/in/photostream/
  30. 30. Chris Ewing Impact Forecasting Aon Benfield Analytics t: +44 (0)207 522 8305 e: [email_address] twitter: @web_gis
  31. 31. References <ul><li>Linked Data </li></ul><ul><ul><li>http://www.w3.org/DesignIssues/LinkedData.html </li></ul></ul><ul><ul><li>http://www.readwriteweb.com/archives/linked_data_is_blooming_why_you_should_care.php </li></ul></ul><ul><ul><li>http://en.wikipedia.org/wiki/Semantic_Web </li></ul></ul><ul><li>RDF </li></ul><ul><ul><li>http://www.w3.org/TR/rdf-concepts/#section-SimpleFacts </li></ul></ul><ul><li>SPARQL </li></ul><ul><ul><li>http://openuplabs.tso.co.uk/datasets </li></ul></ul><ul><li>GeoSPARQL </li></ul><ul><ul><li>http://www.geosparql.org </li></ul></ul><ul><li>Ordnance Survey Linked Data </li></ul><ul><ul><li>http://data.ordnancesurvey.co.uk/.html </li></ul></ul><ul><ul><li>http://johngoodwin225.wordpress.com/2010/10/25/location-location-location-%E2%80%93-exploring-ordnance-survey-linked-data-part-2/ </li></ul></ul><ul><li>Data.gov.uk LinkedData </li></ul><ul><ul><li>http://data.gov.uk/linked-data </li></ul></ul><ul><li>Linked Data and INSPIRE </li></ul><ul><ul><li>http://inspire.jrc.ec.europa.eu/documents/Network_Services/Linked_Data_&_INSPIRE_v101.pdf </li></ul></ul><ul><ul><li>  http://www.dnf.org/images/uploads/guides/20100915_-_Linked_Data_Workshop_Summary_v100.pdf </li></ul></ul>

×