Bernadette Hyland's brief for the W3C

1. The Joy of Data
A cookbook for publishing
Linked Data on the Web
10 minute brief to the W3C Gov’t Linked Data Working Group
29-June 2011
Bernadette Hyland
bhyland@3roundstones.com
Thursday, June 23, 2011 1

2. 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
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3. Setting the scene ...
where should we
focus?
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4. We’ll review
• Converting data into RDF
• The social contract publishers
make
• The importance of announcing
• Where to turn for guidance
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5. • 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!
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6. 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
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7. There is a Process
Identify Model Name Describe Convert Publish
Maintain
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8. Preparation
1. 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.
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9. Modeling the data
2. 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.
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10. Modeling the data
3. 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
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11. 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
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12. 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.
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13. 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)
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14. 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
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15. Take an iterative approach
1. 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)
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16. Describe your
data
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17. 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
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18. 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
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19. In a tart, smoothie or
margarita ... berries
can be combined in
different ways
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20. 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
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21. Announcing the
finished
product!
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22. •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
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23. This work is Copyright © 2011 3 Round Stones Inc.
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