EDF2012: The Web of Data and its Five Stars

The Web of Data and its Five Stars

Richard Cyganiak, DERI, NUI Galway���@cygri

6 June 2012

Realising and Exploiting the EU data cloud

European Data Forum, Copenhagen, Denmark

Generating insight from data

•  Today, data is abundant

•  New middlemen find new ways of getting data to the end user

•  Supply and demand for data higher than ever

•  Analyst's problem is no longer a lack of relevant data, but:

•  Understanding data

•  Assessing applicability

•  Getting it into the right form for use

•  Similar problems inside and outside of the firewall

From the Web ���to the Web of Data

Tim Berners-Lee’s 5-star plan for an open web of data

★ Make data available on the Web under an open license

★★ Make it available as structured data

★★★ Use a non-proprietary format

★★★★ Use URIs to identify things

★★★★★ Link your data to other people’s data ���to provide context

The 0th star

• Data catalog with good metadata

• Make your data findable

Data on the Web, Open License

★

Open Data

Government data catalogs

Open vs. Closed Data used to be closed by default.���

In the future, it will be open by default.

Is open data just for governments?

Good reasons against opening data

•  Privacy

•  Competitive advantage

•  Producing data and charging for it as business model

•  Can't get license from upstream

Business models

Scott Brinker, http://www.chiefmartec.com/2010/01/7-business-models-for-linked-data.html

Data licenses

http://opendefinition.org/licenses/

Structured Data

★★

Enabling re-use

•  Delivering data to end users in different forms

•  Combining data with other data

•  3rd party analysis of data

Formats in government data

•  Good for re-use: MS Excel, CSV, XML, JSON, Microdata

•  Not so good for re-use: Pure websites, MS Word

•  Bad for re-use: PDF

•  Really bad for re-use: Only charts/maps without numbers

Symptom: Screenscraping

Non-Proprietary Formats

★★★

Specialist formats

•  Specialist tools often have specialist formats

•  Few people have the tools

•  Expensive

•  Difficult to re-use

•  (Geospatial tools, statistics packages, etc.)

Non-proprietary formats, open standards

•  CSV (dead simple)

•  XML

•  JSON

•  RDF (good for 4+5 stars)

•  OGC web services

•  OAI-ORE web services

Use URIs as Identifiers

★★★★

http://www.bbc.co.uk/music/artists/79239441-bfd5-4981-a70c-55c3f15c1287

http://data.ordnancesurvey.co.uk/id/postcodeunit/HA99HD

http://opencorporates.com/companies/us_vt/F013910

Turning local identifiers into URIs–Why?

• Make them globally unique

• Clarify authority

• Make them resolvable

• Make them linkable

http://data.ordnancesurvey.co.uk/id/7000000000017765

The schema level

By using URIs, connections that existed only in people's minds can be put explicitly into the data model.

Include Links to Other Data

★★★★★

Hyperlinks are the soul of the Web.���

The Web of Data is no different.

Central Contractor Registration (CCR)

Geonames

Data links

Linked Data Principles

1.  Use URIs to name things (not only documents, but also people, locations, concepts, etc.)

2.  To enable agents (human users and machine agents alike) to look up those names, use HTTP URIs

3.  When someone looks up a URI, provide useful information (structured data in RDF, SPARQL).

4.  Include links to other URIs allowing agents to discover more things

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

Summary

•  In the future, data will be open by default, unless good reason not to

•  Emergence of a web of data

•  “Five-star plan” for getting there, dataset by dataset

•  2 stars: re-usable data!

•  3 stars: open standards!

•  4+5 stars: connect the silos!

Thank You!

[email protected]

@cygri