Loading…

Flash Player 9 (or above) is needed to view presentations.
We have detected that you do not have it on your computer. To install it, go here.

Like this presentation? Why not share!

30 Minute Guide to RDF and Linked Data

on

  • 49,619 views

I gave this presentation at the code4lib 2009 linked data preconference (see http://wiki.code4lib.org/index.php/LinkedData)

I gave this presentation at the code4lib 2009 linked data preconference (see http://wiki.code4lib.org/index.php/LinkedData)

Statistics

Views

Total Views
49,619
Views on SlideShare
47,803
Embed Views
1,816

Actions

Likes
153
Downloads
3,817
Comments
9

35 Embeds 1,816

http://www.semanticlibrary.net 863
http://storify.com 248
http://cinemadata.org 150
http://www.slideshare.net 139
http://wiki.bcmoney-mobiletv.com 110
http://bla-bla.blogspot.com 68
http://semanticlibrary.net 49
http://www.dagoneye.it 28
http://bla-bla.blogspot.pt 25
http://socialsoftware2012.blogspot.com.br 22
http://praveenvaidya.wordpress.com 20
http://whatisprymas.wordpress.com 14
http://socialsoftware2012.blogspot.com 13
http://cadernosemantico.wordpress.com 12
http://tweets.realityseo.com 11
http://www.linkedin.com 7
http://bla-bla.blogspot.com.br 6
http://www.cinemadata.org 5
http://www.e-presentations.us 4
https://twitter.com 3
https://connect.ubc.ca 3
http://rictome.posterous.com 2
http://webcache.googleusercontent.com 2
http://192.30.165.23 1
http://162.243.93.18 1
http://localhost:8084 1
http://bla-bla.blogspot.fr 1
http://datema.org 1
http://www.techgig.com 1
http://bla-bla.blogspot.kr 1
http://translate.googleusercontent.com 1
http://www.lmodules.com 1
http://www.twylah.com 1
http://a0.twimg.com 1
http://www.digitalhumanitieslibrarian.org 1
More...

Accessibility

Categories

Upload Details

Uploaded via as OpenOffice

Usage Rights

CC Attribution-ShareAlike LicenseCC Attribution-ShareAlike License

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

15 of 9 Post a comment

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
  • good tutorial, but download gives an empty file...
    Are you sure you want to
    Your message goes here
    Processing…
  • ex.thing/Person appears to be a class. What if you had another person? Then you wouldn't be able to tell who actually wrote the book in question.
    Are you sure you want to
    Your message goes here
    Processing…
  • good
    Are you sure you want to
    Your message goes here
    Processing…
  • another new concept..this IT world is bringing new concept like anything..
    Are you sure you want to
    Your message goes here
    Processing…
  • The downloaded version is just an empty txt file :(
    Can you send me the pdf version? or can you fix the download process?

    Thank you!
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

30 Minute Guide to RDF and Linked Data 30 Minute Guide to RDF and Linked Data Presentation Transcript

  • The thirty minute guide to RDF and Linked Data Originally created by Ian Davis and Tom Heath, but please share and reuse
  • What is RDF? RDF is the data format for linked data  Resource Description Framework  In essence a simple data model  It's about writing down relations between things  See http://www.w3.org/RDF/ 
  • What is RDF for? The web is a global, universal information space for  documents Can we do same for data?  Make the web into a database?  RDF is the data format for that database   
  • Imagine a typical database table
  • The rows represent the “things”
  • Columns represent the “properties”
  • Intersections represent properties of things
  • We can draw a picture of that information
  • The essence of RDF: the “triple”
  • Selecting multiple properties
  • Multiple properties graphically
  • Relations between “things”
  • Graphs Think in terms of graphs, not XML or documents  Nodes in graph are things, arcs are relationship  between things
  • Using the Web's Infrastructure For a web-scale database we need to be able to  identify things globally and uniquely URIs (URLs) already provide those capabilities  Name things with URIs, specifically http://  This is the key to linked data  
  • Graphs can have named things (resources)
  • And text values (literals)
  • And numeric values (also literals)
  • And named relations
  • Simple rules The URI identifies the thing you are describing  If two people create data using the same URI then  they are describing the same thing That makes it easy to merge data from different  sources together RDF data can use URIs from many different  websites
  • RDF merging 1 (graph)
  • RDF merging 2 (graph)
  • RDF merginf 3 (graph)
  • RDF merging 1 (XML) <r d f : De s c r i p t i o n r d f : a b o u t =quot; h t t p : / / e x . o r g / t h i n g / p e r s o n quot; > <p r o p : n a me >S h a k e s p e a r e </ p r o p : n a me > <p r o p : wr o t e r d f : r e s o u r c e =quot; h t t p : / / e x . o r g / t h i n g / b o o k quot; / > </r d f : De s c r i p t i o n > <r d f : De s c r i p t i o n r d f : a b o u t =quot; h t t p : / / e x . o r g / t h i n g / b o o k quot; > <p r o p : t i t l e >Ki n g L e a r </ p r o p : t i t l e > </r d f : De s c r i p t i o n >
  • RDF merging 2 (XML) <r d f : De s c r i p t i o n r d f : a b o u t =quot; h t t p : / / e x . o r g / t h i n g / p e r s o n quot; > <p r o p : n a me >S h a k e s p e a r e </ p r o p : n a me > <p r o p : wr o t e r d f : r e s o u r c e =quot; h t t p : / / e x . o r g / t h i n g / b o o k quot; / > </r d f : De s c r i p t i o n > <r d f : De s c r i p t i o n r d f : a b o u t =quot; h t t p : / / e x . o r g / t h i n g / b o o k quot; > <p r o p : t i t l e >Ki n g L e a r </ p r o p : t i t l e > </r d f : De s c r i p t i o n > <r d f : De s c r i p t i o n
  • RDF merging 3 (XML) <r d f : De s c r i p t i o n r d f : a b o u t =quot; h t t p : / / e x . o r g / t h i n g / p e r s o n quot; > <p r o p : n a me >S h a k e s p e a r e </ p r o p : n a me > <p r o p : wr o t e r d f : r e s o u r c e =quot; h t t p : / / e x . o r g / t h i n g / b o o k quot; / > </r d f : De s c r i p t i o n > <r d f : De s c r i p t i o n r d f : a b o u t =quot; h t t p : / / e x . o r g / t h i n g / b o o k quot; > <p r o p : t i t l e >Ki n g L e a r </ p r o p : t i t l e > <p r o p : d a t e >1 6 0 5 </ p r o p : d a t e > <p r o p : a u t h o r e d r d f : r e s o u r c e =quot; h t t p : / / e x . o r g / t h i n g / e n g l a n d quot; /
  • URIs are active This is the web - URIs can be retrieved  Fetch any URI from a graph to lookup more RDF  about it ...which can be safely merged − ...and may have other URIs which can be looked up − The result is a way to amass more information  about things simply by following links
  • SPARQL Once you have new data you can query it  SPARQL is the standard query language for linked  data It works by matching patterns in the graph 
  • Getting involved As a data publisher you need to...  convert some data to RDF − publish it on your website like you do with HTML − As a data consumer you need to...  learn one of the open source or commercial RDF − toolkits find and retrieve the data you need − use sparql to extract the useful bits for the task at hand −
  • Linked data principles Use URIs as names for things  Use HTTP URIs so people can look up those  names When someone looks up a URI, provide useful  RDF information Include RDF statements that link to other URIs so  they can discover related things
  • Five steps to publishing linked data 1. Understand the Principles 2. Understand your Data 3. Choose URIs for Things in your Data 4. Set up Your Infrastructure 5. Link to other Data Sets
  • Step 1: understand the principles Use URIs as names for things  anything, not just documents − you are not your homepage − information resources and non-information resources − Use HTTP URIs  globally unique names, distributed ownership − allows people to look up those names −
  • Step 1: Understand the principles Provide useful information in RDF  when someone looks up a URI − Include RDF links to other URIs  to enable discovery of related information −
  • Step 2: Understand your data What are the key things present in your data? People Concepts − Places Photos − Events Comments − Books Reviews − Films − Musicians −
  • Step 2: Understand your data What vocabularies can be used to describe these?   FOAF, SIOC, Dublin Core, geo, SKOS, Review  Principles  Reuse, don't reinvent − Mix liberally −
  • Step 3: Choosing URIs Use HTTP URIs  Keep out of other peoples' namespaces  http://www.imdb.com/title/tt0441773/  http://myfilms.com/tt0441773 Abstract away from implementation details  http://dbpedia.org/resource/Berlin  http://www4.wiwiss.fu-berlin.de:2020/demos/dbpedia/cgi-bin/resources.php?id=Berlin Hash or Slash?  http://mydomain.com/foaf.rdf#me  http://mydomain.com/id/me
  • Step 3: Common patterns for URIs http://dbpedia.org/resource/New_York_City ← Thing  http://dbpedia.org/data/New_York_City ← RDF data  http://dbpedia.org/page/New_York_City ← HTML page  http://example.com/thing ← Thing  http://example.com/thing/rdf ← RDF data  http://example.com/thing/html ← HTML page  http://example.com/thing ← Thing  http://example.com/thing.rdf ← RDF data  http://example.com/thing.html ← HTML page 
  • Step 4: Setup infrastructure
  • Step 4: Setup infrastructure Testing your content negotiation  Install the LiveHTTPHeaders and Modify Headers − extensions for Firefox Try LiveHTTPHeaders against a URI − http://dbpedia.org/resource/Linked_Data  Modify your headers to ask for application/rdf+xml − What do you get back? − Do the same with cURL − http://dowhatimean.net/2007/02/debugging-semantic- −
  • Step 5: Link to other available data sets
  • Step 5: Link to other data sets Popular Predicates for Linking owl:sameAs foaf:depiction foaf:homepage foaf:page foaf:topic foaf:primaryTopic foaf:based_near rdfs:seeAlso foaf:maker/foaf:made
  • Step 5: Link to other data sets Linking Algorithms  String Matching  e.g. Lexical Distance between labels − Common Key Matching  e.g. ISBN, Musicbrainz Ids − Property-based Matching  Do these two things have the same label, type and − coordinates? Aim for reciprocal links 
  • Summary RDF is the data format for Linked Data RDF uses URIs to name things, preferably HTTP When a URI is fetched send a useful RDF description of the thing the URI names RDF describes relationships between things Link to other Data Sets