UKOLN is supported by: Linked Data and the Semantic Web - What are they and should I care? 6 th November 2009 UKOLN Staff Seminar, University of Bath, UK Adrian Stevenson

semantics is … devoted to the study of meaning … on the syntactic levels of words, phrases, sentences http://en.wikipedia.org/wiki/Semantic

semantics is … devoted to the study of meaning … on the syntactic levels of words, phrases, sentences

http://en.wikipedia.org/wiki/Semantic

“ The Semantic Web is a web of data , in some ways like a global database” 1 “ first step is putting data on the Web in a form that machines can naturally understand... This creates what I call a Semantic Web - a web of data that can be processed directly or indirectly by machines” 2 1. http://www.w3.org/DesignIssues/Semantic.html 2. Tim Berners-Lee, Weaving the Web . Harper, San Francisco. 1999.

“ The Semantic Web is a web of data , in some ways like a global database” 1

“ first step is putting data on the Web in a form that machines can naturally understand... This creates what I call a Semantic Web - a web of data that can be processed directly or indirectly by machines” 2

1. http://www.w3.org/DesignIssues/Semantic.html

2. Tim Berners-Lee, Weaving the Web . Harper, San Francisco. 1999.

“ The term Linked Data refers to a set of best practices for publishing and connecting structured data on the Web.” “ the Semantic Web is the goal or end result… Linked Data provides the means to reach that goal” From ‘ Linked Data: The Story So Far ’ - Heath, Bizer and Berners-Lee 2009

“ The term Linked Data refers to a set of best practices for publishing and connecting structured data on the Web.”

“ the Semantic Web is the goal or end result… Linked Data provides the means to reach that goal”

From ‘ Linked Data: The Story So Far ’ - Heath, Bizer and Berners-Lee 2009

The Web We’re Used To Made by humans for humans Primarily documents Machines not very welcome Data silos

Made by humans for humans

Primarily documents

Machines not very welcome

Data silos

Web of Linked Data In 1998 the idea from Tim Berners-Lee of ‘linked data’ took shape Designed for machines first It primarily links data about ‘things’, not documents … but it is for humans in the end

In 1998 the idea from Tim Berners-Lee of ‘linked data’ took shape

Designed for machines first

It primarily links data about ‘things’, not documents

… but it is for humans in the end

But haven’t we been putting data on the web for years? In CSV , relational databases, XML etc? Well yes, but these approaches are not so easy to integrate Web 2.0 mashups work against a fixed set of data sources Linked Data applications operate on top of an unbound, global data space.

But haven’t we been putting data on the web for years?

In CSV , relational databases, XML etc?

Well yes, but these approaches are not so easy to integrate

Web 2.0 mashups work against a fixed set of data sources

Linked Data applications operate on top of an unbound, global data space.

So what’s happening now?

“ Sir Tim Berners-Lee, the inventor of the world wide web, will help the British government to make its data more easily available online … I have asked Sir Tim Berners-Lee … to help us drive the opening up of access to Government data in the web” Prime Minister Gordon Brown, 10 th June 2009 "What you find if you deal with people in government departments is that they hug their database, hold it really close”. Tim Berners-Lee, 10 th June 2009 We shall see …

“ Sir Tim Berners-Lee, the inventor of the world wide web, will help the British government to make its data more easily available online … I have asked Sir Tim Berners-Lee … to help us drive the opening up of access to Government data in the web” Prime Minister Gordon Brown, 10 th June 2009

"What you find if you deal with people in government departments is that they hug their database, hold it really close”. Tim Berners-Lee, 10 th June 2009

We shall see …

data.gov.uk

BBC Music BETA

A little bit of the techy stuff

Linked Data is … A way of publishing data on the web that: Encourages reuse Reduces redundancy Maximises inter-connectedness Enables network effects So how is this achieved?

A way of publishing data on the web that:

Encourages reuse

Reduces redundancy

Maximises inter-connectedness

Enables network effects

So how is this achieved?

Presentational tagging – HTML <h1>Agilitas Physiotherapy Centre</h1> <p>Welcome to the Agilitas Physiotherapy Centre home page. Do you feel pain? Have you had an injury? Let our staff Lisa Davenport, our secretary Kelly Townsend, and Steve Matthews take care of your body and soul.</p> <h2>Consultation hours</h2> Mon 11am - 7pm<br/> Tue 11am - 7pm<br/> Wed 3pm - 7pm<br/> Thu 11am - 7pm<br/> Fri 11am - 3pm <p> But note that we do not offer consultation during the weeks of the <a href=&quot;. . .&quot;>State Of Origin</a> games.</p>

<h1>Agilitas Physiotherapy Centre</h1> <p>Welcome to the Agilitas Physiotherapy Centre home page. Do you feel pain? Have you had an injury? Let our staff Lisa Davenport, our secretary Kelly Townsend, and Steve Matthews take care of your body and soul.</p> <h2>Consultation hours</h2> Mon 11am - 7pm<br/> Tue 11am - 7pm<br/> Wed 3pm - 7pm<br/> Thu 11am - 7pm<br/> Fri 11am - 3pm

<p> But note that we do not offer consultation during the weeks of the <a href=&quot;. . .&quot;>State Of Origin</a> games.</p>

Semantic tagging <company> <treatmentOffered>Physiotherapy</treatmentOffered> <companyName>Agilitas Physiotherapy Centre</companyName> <staff> <therapist>Lisa Davenport</therapist> <therapist>Steve Matthews</therapist> <secretary>Kelly Townsend</secretary> </staff> </company>

<company>

<treatmentOffered>Physiotherapy</treatmentOffered>

<companyName>Agilitas Physiotherapy Centre</companyName>

<staff>

<therapist>Lisa Davenport</therapist> <therapist>Steve Matthews</therapist>

<secretary>Kelly Townsend</secretary>

</staff>

</company>

Tim BL’s Linked Data Design Issues 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 so that they can discover more things. From http://www.w3.org/DesignIssues/LinkedData.html

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 so that they can discover more things.

From http://www.w3.org/DesignIssues/LinkedData.html

URIs and HTTP A “Uniform Resource Identifier (URI) provides a simple and extensible means for identifying a resource –RFC 3986 A URL is a type of URI HTTP URIs can be ‘de-referenced’ HTTP URIs are used for “real world” things http://adrianstevenson.com/id/me http://dbpedia.org/page/Tim_Berners-Lee

A “Uniform Resource Identifier (URI) provides a simple and extensible means for identifying a resource –RFC 3986

A URL is a type of URI

HTTP URIs can be ‘de-referenced’

HTTP URIs are used for “real world” things

http://adrianstevenson.com/id/me

http://dbpedia.org/page/Tim_Berners-Lee

RDF Resource Description Framework “ a language for representing information about resources in the World Wide Web” “ RDF can also be used to represent information about things that can be identified on the Web, even when they cannot be directly retrieved on the Web” Describes relations based on triples S ubject-object-predicate http://www.w3.org/TR/REC-rdf-syntax/

Resource Description Framework

“ a language for representing information about resources in the World Wide Web”

“ RDF can also be used to represent information about things that can be identified on the Web, even when they cannot be directly retrieved on the Web”

Describes relations based on triples

S ubject-object-predicate

http://www.w3.org/TR/REC-rdf-syntax/

Heroes has a creator whose name is David Bowie Subject Predicate Object

Heroes

has a

creator

whose name is

David Bowie

Linked Data in Use

Publishing Linked Data RDFizers – convert data formats into RDF D2R Server – creates linked data from relational databases SparqPlug – Extracts linked data from HTML … . Many others

RDFizers – convert data formats into RDF

D2R Server – creates linked data from relational databases

SparqPlug – Extracts linked data from HTML

… . Many others

Linked Data Applications Linked Data Browsers – navigate between data sources Disco Tabulator Marbles Linked Data Search Engines For humans – Falcons, SWSE For apps – Swoogle, Sindice

Linked Data Browsers – navigate between data sources

Disco

Tabulator

Marbles

Linked Data Search Engines

For humans – Falcons, SWSE

For apps – Swoogle, Sindice

Tracks provenance of data Merges data about the same thing from different sources

Tracks provenance of data

Merges data about the same thing from different sources

User can explore the underlying data structures Can search for objects, concepts or documents

User can explore the underlying data structures

Can search for objects, concepts or documents

Provides interface (API) that other linked data apps can use Rationale: new linked data apps shouldn’t need to implement their own infrastructure for crawling and indexing web of data

Provides interface (API) that other linked data apps can use

Rationale: new linked data apps shouldn’t need to implement their own infrastructure for crawling and indexing web of data

Some issues To RDF or not to RDF Usability Sustainability Provenance Licensing Reliability

To RDF or not to RDF

Usability

Sustainability

Provenance

Licensing

Reliability

I Linked Data Therefore I RDF

Sustainability Ed Summers at the Library of Congress created http://lcsh.info Linked Data interface for LOC subject headings People started using it

Ed Summers at the Library of Congress created http://lcsh.info

Linked Data interface for LOC subject headings

People started using it

Library of Congress Subject Headings

Data Licensing RDF Book Mashup makes information about books, their authors, reviews, and online bookstores available on the Semantic Web Uses Amazon Web Services but contravenes terms and conditions

RDF Book Mashup

makes information about books, their authors, reviews, and online bookstores available on the Semantic Web

Uses Amazon Web Services but contravenes terms and conditions

Provenance OK if data ‘watermarked’ But can often be a problem VOID can help (apparently!)

OK if data ‘watermarked’

But can often be a problem

VOID can help (apparently!)

Woolyish conclusion Some interesting recent developments and sense of momentum Central Gov’t interested … but still much to do if the semantic web and linked data are to really take hold

Some interesting recent developments and sense of momentum

Central Gov’t interested

… but still much to do if the semantic web and linked data are to really take hold

Questions? http://www.twitter.com/adrianstevenson [email_address]

http://www.twitter.com/adrianstevenson

[email_address]

CC Attribution Some sections of this presentation adapted from: An Introduction to Linked Data , by Tom Heath The Semantic Web – An Introduction by Owen Stephens Using Linked Data as a Learning Resource Recommendation System by Chris Clarke This presentation available under creative commons Noncommercial-Share Alike

Some sections of this presentation adapted from:

An Introduction to Linked Data , by Tom Heath

The Semantic Web – An Introduction by Owen Stephens

Using Linked Data as a Learning Resource Recommendation System by Chris Clarke

This presentation available under creative commons Noncommercial-Share Alike