Linking Library DataELAG 2011 Workshop

Jindřich Mynarz @jindrichmynarz

linked data is sooo 2009

Workshop

• Introductiono Motivationo Involved technologies

• Discussiono Key questionso Potential issues

• Practical linking

Shared document: bit.ly/linking-library-dataTwitter hashtag: #elag2011

conversion

lots about

linking

little about

library links

raw data

linked data

Key technologies

• URIs• RDF• SPARQL• Linked data

URIs

• Uniform Resource Identifierso <http://example.com>

• "Cool URIs"o resolvableo stableo implement content negotiation

Learn how the RDF looks like

• Data format for formalizing directed graphs.• Standard for data interchange on the Web.• Unit of RDF is a triple.

Step 1: a triple

Step 2: triples

Step 3: a graph

Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/

Step 4: linked data

Learn how to SPARQL

• Query language for RDFPREFIX ex: <http://example.com>SELECT [DISTINCT] ?what [FROM ?where]WHERE {  ?triplePattern} [LIMIT ?limit][ORDER BY ?variable] 

Linked data

1. Use URIs as names for things2. Use HTTP URIs so that people can look up those names.3. When someone looks up a URI, provide useful

information, using the standards (RDF, SPARQL)4. Include links to other URIs. so that they can discover more

things.

Linking data

• linking... o is a continuous integration of heterogeneous

dataspaces? o creates context?o is a job for librarians? Or machines?o is good?

@href is a blunt instrument

typed links

=    identity~    similarity>    hierarchy?    aboutness

typed links

Discussion

• How to find datasets suitable for interlinking? • How to make my dataset worth linking to?• How to encourage others to link to my data?• What is the added value of links? • How to determine the quality of a link?• How to maintain links?

find and examine data

added value of links

link baiting

link maintenance

Linking

• Record linkage, identity resolution, duplicate detection, instance matching, co-reference detection

• Determinism: o Deterministic (e.g., dictionary-based)o Probabilistic (e.g., graph matching)

• Level:o Schema (e.g., ontology mapping)o Instances (e.g., record linkage)

Linking

1. Untyped links to typed links.2. Literals to links.3. Links to other links.

Interlinking with Silk

• Silk is an interlinking framework for instance matching.• Uses the link specification language to describe the

interlinking process.• Powerful and relatively easy-to-use.

Link specification language

• Your turn!

connect the dots

get this

or this

the end.