graphic with four colored squares
Cover page images (keys)

Mission Possible: Deploying Government Linked Data (Pt3)

Sandro Hawke, (, W3C/MIT, @sandhawke
John L. Sheridan, @johnlsheridan
gov 2.0 expo, May 25-26, 2010, Washington DC (wiki)

Part 3

Publishing Triples on the Web

  1. The Mechanics of Publication
  2. The Politics of Publication

Patterns for Publishing

Mechanics of Publication

What do you need to publish your triples?



Static Documents

Generate by hand, or output from existing systems.

Web Platforms

Drupal 6, Drupal 7

Semantic MediaWiki

Some RDFa is easy.


D2R Server

Maybe built into MySQL, Oracle, ...

RDB2RDF Working Group


Custom Servers

jena rdflib redland swipl

Linked Data API

For example:


See project slides

Data Changes

This is an API. Every change affects someone.

Design for change.

The World Changes

A set of triples should be true for some time range

Suggestion: use dc:temporal to declare that time range.

One URL for archival copy:

Another URL for "latest":

This is good practice for many kinds of web pages.

Link among the versions.


Similar archive/latest mechanism, but different reasons.

"restated financial statements" for some time period.

Metadata can indicate the difference, causes.

Push and Pull Feeds

Dataset Dynamics


dcat Data Catalog Vocabulary

Politics of Publication

Tim Berners-Lee's five stars:

  1. Publish the data on the Web in any format (eg .pdf)
  2. Publish in a machine-readable format (eg .xls)
  3. Publish in a non-proprietary format (eg .csv)
  4. Publish as RDF Linked Data (eg .rdf)
  5. Establish useful links between resources

Maybe you're already at 2 or 3.

Jumping in at 5 might be easiest.

Aligning Governance

Continuity Policies

Who will serve the URI if the agency changes names?

Who will serve the URI if the agency is shut down?

Redirections vs Content

Role of Archives Organizations

Maintaining Provenance

Next Steps

Local Semantic Web Meetups

Participate in W3C eGov Interest Group

Email subject "tutorial"