Potentials and Benefits of Linked Open Data

Dr. Sören Auer

What‘s wrong with Open Data?

Creating Knowledge out of Interlinked Data

Creating Knowledge out of Interlinked Data

1st Resource Download Attempt

Creating Knowledge out of Interlinked Data

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Creating Knowledge out of Interlinked Data

After Installing 7zip for opening .gz files

Creating Knowledge out of Interlinked Data

Creating Knowledge out of Interlinked Data

3rd Resource Download Attempt

Creating Knowledge out of Interlinked Data

5th Resource Download Attempt

Creating Knowledge out of Interlinked Data

Creating Knowledge out of Interlinked Data

Giving up

Creating Knowledge out of Interlinked Data

<kindergarten>

<name>Seven Dwarfs</name>

<location>...</location>

<description>...</description>

</kindergarten>

Publishing Data about Kindergartens in XML (1)

Creating Knowledge out of Interlinked Data

<child_care name=„Seven Dwarfs“>

<address>

<street>...</street>

<zip>...</zip>

</address>

<text>...</text>

</child_care>

Publishing Data about Kindergartens in XML (2)

Creating Knowledge out of Interlinked Data

<daycare id=„Seven Dwarfs“

address=„...“>

. . .

</daycare>

Publishing Data about Kindergartens in XML (3)

Creating Knowledge out of Interlinked Data

Syntactic heterogenity – different

trees

Semantic heterogenity – different

tags and attributes (e.g. kindergarten,

child_care, daycare)

<kindergarten>

<name>Seven Dwarfs</name>

<location>...</location>

<description>...</description>

</kindergarten>

<child_care name=„Seven Dwarfs“>

<address>

<street>...</street>

<zip>...</zip>

</address>

<text>...</text>

</child_care>

<daycare id=„Seven Dwarfs“

address=„...“>

. . .

</ daycare >

Creating Knowledge out of Interlinked Data

Kindergarten Location Description …

Seven Dwarfs Rosentalgasse 9, 04105

… …

… … … …

Maybe CSV helps?

Child_care street Zip textSeven Dwarfs Rosentalgasse 04105 …

… … … …

Type Name Location FeaturesDaycare Seven Dwarfs 42.052384|

13.273679…

… … … …

Creating Knowledge out of Interlinked Data

Imagine you have 10.000 open data files

describing child care from communities

all over Europe all in different XML, CSV,

Excel, JSON, … formats

And then you want to look into polution,

road congestion, health care, …

A nightmare …

Creating Knowledge out of Interlinked Data

Distribution of file formats at PublicData.eu

Creating Knowledge out of Interlinked Data

How can we fix open data?

Creating Knowledge out of Interlinked Data

• Increasing data literacy???

• Organizing hackdays, hackathons???

• Publish more data???

Yes, but this won‘t scale

We need also:

• Standard formats, which preserve semantic: RDF

• Reuse vocabularies

• Visualizatuion widgets, mashups, apps, which can

make sense out of those vocabularies

How can we fix Open Data?

Creating Knowledge out of Interlinked Data 1. Uses RDF Data Model

Linked Data in a Nutshell

LOD-MeetUp

Amsterdam

24.3.2013

OKFNorganizes

starts

takesPlaceIn

2. Is serialised in triples:OKFN organizes LOD-MeetUp .LOD-MeetUp starts “20130324”^^xsd:date .LOD-MeetUp takesPlaceAt Amsterdam .

3. Uses Content-negotiation

Subject Predicate Object

Creating Knowledge out of Interlinked Data

Seven_Dwarfs rdf:type Kindergarten

Seven_Dwarfs rdfs:label „Seven Dwarfs“

Seven_Dwarfs foaf:location „Rosentalgasse 9“

Seven_Dwarfs rdfs:description „...“

...

Different Kindergarten descriptions also might look different, but

there will be definitely less variety than with XML or CSV

You can mix and mesh different vocabularies (RDF, RDFS, FOAF)

More information can be added without destroying the data

structure

7 Dwarfs in RDF

Creating Knowledge out of Interlinked Data

• Publish Open Data in RDF reusing vocabularies

which can be understood and combined by apps in

unforeseen ways (e.g. visualization widgets)

What has to be done?

Where we are now

Where we should be

make your stuff available on the Web (whatever format) under an open license

link your data

use URIs to denote things

use non-proprietary formats(e.g., CSV instead of Excel)

make it available as structured data(e.g., Excel instead of image scan of a table)

Creating Knowledge out of Interlinked Data

How can we lift Open Data to Linked Open Data?

Creating Knowledge out of Interlinked Data

All CSV on PublicData.eu is transformed in RDF

Creating Knowledge out of Interlinked Data

Creating Knowledge out of Interlinked Data

• Automatic CSV to

RDF

transformation

won‘t render good

results

• Mappings Wiki

enables the

crowdsourcing of

mappings

Mapping Wiki

Creating Knowledge out of Interlinked Data 1 {{CSV2RDFHeader}}

23 ...45 {{RelCSV2RDF6 | name = default-mapping7 | header = 18 | omitRows = -19 | omitCols = -110 | delimiter =11 | col1 = Department Family12 | col2 = Entity13 | col3 = Payment Date^^xsd:date14 | col4 = rdf:type15 | col5 = Cost Centre Name16 | col6 = Supplier17 | col7 = Transaction No.18 | col8 = Line Amount19 | col9 = Invoice Total^^xsd:decimal20 }}

CSV2RDF Mapping Syntax

Creating Knowledge out of Interlinked Data

How can we make this happen?

Expl

orati

onW

idge

ts Spatial faceted-browsing

Faceted-browsing

Statisticalvisualization

Entity-/faceted-Based browsing

Domain specificvisualizations

… …

Ope

n D

atas

ets

Dat

a Po

rtal

• Dataset analysis (size, vocabularies, properties)• Selection of suitable visualization widgets

SemMap OntoWiki

Creating Knowledge out of Interlinked Data

Browsing Statistical Data with CubeViz

Creating Knowledge out of Interlinked Data

Browsing Spatial Data with SemMap

Creating Knowledge out of Interlinked Data

Inter-linking/ Fusing

Classifi-cation/ Enrichment

Quality Analysis

Evolution / Repair

Search/ Browsing/ Exploration

Extraction

Storage/ Querying

Manual revision/ authoring

LOD Lifecyclesupported byDebian basedLOD2 Stack

http://stack.lod2.eu

Creating Knowledge out of Interlinked Data

• Open Data will only scale when ist Linked Open Data

• The RDF data model helps to reduce syntactic and

semantic heterogenity

• When Open Data is published as LOD adhering to

standard vocabularies, visualization widgets,

mashups, apps etc. can be applied to the data at

runtime and in possibly unforeseen ways

• By ultimately reducing the entrance and usage

barrier LOD will facilitate long-tail applications

Take home

Creating Knowledge out of Interlinked Data

Thank You!!!

http://lod2.euhttp://aksw.org

The emerging Web of Data

20082007

20082008

20082009

2009

2010

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

Creating Knowledge out of Interlinked Data

Web server

Web server

Problem: Try to search for these things on the current Web:

• Apartments near German-English bilingual childcare in Leipzig

• ERP service providers with offices in Vienna and London

• Researchers working on multimedia topics in Eastern Europe

Information is available on the Web, but opaque to current search.

Why do we need the Linked Open Data

leipzig.deHas everything about childcare in Leipzig.

Immobilienscout.deKnows all about real estate offers in GermanyDB

Web server

DB

Web server

Search engineHTML HTML

RDF RDF

Solution: complement text on Web pages with structured linked open data & intelligently combine/integrate/join such structured information from different sources: