The Joy of DataA cookbook for publishing Linked Data on the Web

Bernadette Hyland, CEO3 Round Stones, Inc

bhyland@3roundstones.com

A pragmatic approach to

publishing & consuming Linked Data

Agenda• Setting the scene

• Ingredients ... we use a cooking analogy

• Open standards & best practices

• Data modeling without context

• Social contract as a publisher

• Next steps

Setting the scene ...

where should we focus?

We’ll review •Converting data into RDF

•The social contract publishers make

•The importance of announcing

•Where to turn for guidance

Why should we care?• We pretend our organizations are hierarchical -- they aren’t

• Information is power.

• Combining information from different sources is very powerful.

• The US data warehouse market in 2010 was $10B

• In 2012 expected to grow to $13.5B

World changing phenomenon

• Using Linked Data approach, we can begin to address the non-hierarchical nature of our organizations

• We can combine information sources

• The W3C has defined standards that enable interoperability and allow us to freely move data

We are sowing the seeds for nothing

short of a revolution

What does it take?•The ingredients list ...

•Thinking differently about your data

•Modeling for re-use

•Summary of process in 7 steps

“The change from atoms to bits is irrevocable and unstoppable”

Being Digital by Nicolas Negroponte

We use URIs to describe both bits & atoms ...

•Information resources are things that computers understand, e.g., Web pages, images, CSS files, etc.

•Non-information resources are atoms, e.g., people, places, events, things, concepts, etc.

• A different way of thinking about data

• The Open World Assumption

• Lots of URIs

• To be citizen of the world (not everyone speaks English)

• To publish useful information & announce it!

Peeling the

onion ....

Machine readable

and Human Readable (or edible)

Publish machine & human readable content

• Machine readable format

• Human-readable descriptions of your data set

• Increase visibility with search engines

• Include RDFa or other microformats

• Publish a voID description of your RDF dataset

Paid search

100%

90%

80%

70%

60%

50%

40%

30%0% 10% 20% 30% 40% 50% 60%

House email

SEO

Marketers Reporting “Great” Return on Investment

Usa

ge >

>>

Banners, buttons

Text-link ads

Affiliate MarketingBehavioraltargetingContextual

targeting

Pop-ups/pop-unders

Rich media/video

Rented emaillists

Model without

context

There is a Process

PublishConvertDescribeNameModelIdentify

Maintain

Preparation1.Leverage what exists

• Request a copy of the logical and physical model of the database(s)

• Obtain data extracts (i.e., databases and/or spreadsheets) or create data in a way that can be replicated.

Modeling the data2. Model data without context to allow for

reuse and easier merging of data sets

•Traditional DBAs organize data for specified Web services or applications.

•With LD, application logic does not drive the data schema, concepts, etc.

Modeling the data3.Look for real world objects of interest (e.g., people, places,

things, locations, etc.) and model them.

• Investigate how others are already modeling similar or related data.

• Look for duplication and normalize the data

• Use common sense to decide whether or not to make link

Modeling the data ...4. Connect data from different sources and authoritative

vocabularies (see list of popular vocabularies below).

• Use URIs as names for your objects

Modeling the data ...

• Put aside immediate needs of any application

• Don’t think about how an application will use your data

• Do think about time and how the data will change over time.

Convert, Publish & Maintain

5. Write a script or process to convert the data set repeatedly

6. Publish to the Web and announce it! (more details shortly)

7. Maintenance strategy (more details in the social contract at the end)

Take the plunge ... Be forgiving

• Simplistic data models can still be useful

• Better to make progress with something rather than do nothing because we cannot be comprehensive and complete

Take an iterative approach1. Review of modeling decisions

2. Review vocabularies chosen and developed

3. Modify/update data conversion scripts

4. Do a maintenance walk-through with real use cases

5. Show how to explore data with SPARQL and visualizations

6. Discuss a persistent identifier strategy (think PURLs)

shared innovation™

29

Describe your

data

Data stewards should....

• Make data accessible via the Web’s standard access mechanism, specifically http URIs

• Represent data in a common format, such as RDF/XML, Notation-3 (N3), Turtle, N-Triples, RDFa, and RDF/JSON

• Provide self describing data

Linked Data Formats• RDF/XML - RDF for XML pipelines

• Turtle - Human-readable RDF

• XHTML with GRDDL transformation

• XHTML with embedded RDFa

• RDF Schema - Describing structure

In a tart, smoothie or margarita ... berries

can be combined in different ways

Merging data

Guidelines for merging

• URIs name the resources we are describing

• Two people using the same URI are describing the same thing

• The same URI in two datasets means the same thing

• Graphs from several different sources can be merged;

• Resources with the same URI are considered identical;

• No limitations on which graphs can be merged.

Announcing the

finished product!

•Inform the LOD developer community (linkeddata.org, W3 lists)

•Announce to search engines (RDFa hints, register to make accessible)•Publish human readable descriptions•Encourage interlinking•Publish schema as voID •Include SPARQL endpoint

17%

49%

16%

13%4%

6 months12 months18 months24 monthsMore than 24 months

ACCEPTABLE ROI FOR IT

The Social Contract ... The not so fine print

• LOD is a social contract to provide the public with information

• Follow best practices for modeling

• Carefully consider your URI strategy

• Ensure that your LOD remains available where you say it will be

• Publish voID description

• For a government agency ... a data policy is “a must”• specify data quality and retention, treatment of data thru

secondary sources, restrictions for use, frequency of updates, public participation, and applicability of this data policy

We’ve created

someting quite beautiful

http://linkeddatabook.com/editions/1.0/

http://3roundstones.com/linking-enterprise-data/

Reading

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