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Publishing Datasets

nevali
April 18, 2012

Publishing Datasets

A short guide to describing Linked Open Data (LOD) datasets in RDF.

nevali

April 18, 2012
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  1. Archive Development • Your data should ideally exist within a

    conceptual hierarchy (even if it's a single- level hierarchy). • The aim is to make it easy for consumers to discover and use your data, which rich descriptions and links make possible. Implications
  2. Archive Development • Express subsets as subsidiary resources, but keep

    the canonical item URIs at close to the top level as is reasonable. • You might wish to think about organising these hierarchies around conceptual classes: e.g., /articles, /books, /places.
  3. Archive Development • Publish documents at the root dataset URIs

    which describe the sets. • Include information about URI patterns, endpoints, and links to example resources and subsets. • The document is the dataset: e.g., /items is an instance of void:Dataset. Implications
  4. Archive Development • If you can, publish a dataset description

    at your site root and at /.well-­‐known/void. • Within your sets, include descriptions of your text search and SPARQL endpoints, if you have them. • Describe any data dumps that you make available. • Arrange your sets so that clients can traverse them and retrieve their contents. Implications
  5. Archive Development • If you’re able to, include links to

    each of the items within the set using rdfs:seeAlso. • To paginate, link to the first, next, previous and last pages in the set using the XHV terms (e.g., xhv:first). • Order your data by most-recently-modified first to prioritise updates when consumers iterate the set.
  6. Archive Development • If you have data dumps available, link

    to them with void:DataDump. • Include a description of the dump (the target of that link) detailing the creation/ modification dates and MIME type of the dump resource.
  7. Archive Development • Provide dumps as .zip files or gzipped

    single-file RDF/XML (amongst other formats). • Within .zip files, put an RDF/XML file named index.rdf at the root which describes the resources in the dump using relative paths.
  8. Archive Development • Where subsets are organised around classes, describe

    them using void:classPartition and void:class if you can. • Otherwise, use void:subset to reference them. • In subsets, link back to the parent using void:inDataSet.
  9. Archive Development • If possible, use the Semantic Web extensions

    to your Sitemap to describe the datasets (alongside your VoID descriptions).
  10. Archive Development • If possible, include information about each of

    the items in the sets which contain them. • There’s little sense in including all of the information about something — consider what you would typically present in a browsing interface. Implications
  11. Archive Development • Where you include depictions of items, try

    to describe those image resources — the MIME types, and dimensions (using exif:imageWidth and exif:imageHeight).
  12. Archive Development • Rights matter! Include copyright and licensing information

    in the dataset descriptions. • Publish rights information for both the data in the documents and (where applicable) the things described by those documents. • The DMCI Metadata Terms schema includes predicates to aid this, and for many sets the Creative Commons ontology may also be useful.
  13. Archive Development • The primary aim is building a web

    of linked and linkable data. • Don’t assume all consumers will want to only use your data, nor ingest it all into their own triple-stores in order to process or run queries upon it. Implications
  14. Archive Development • SPARQL, search endpoints and data dumps are

    really useful features which enable a variety of interesting applications and they’re worth providing if you can — but not at the cost of data you can link to.
  15. Archive Development • http://vocab.deri.ie/void • Vocabulary of Interlinked Datasets (VoID)

    • http://vocab.deri.ie/void/autodiscovery • VoID Autodiscovery via a RFC5785 .well-­‐known resource. • http://purl.org/NET/mediatypes • Linked data for MIME types (for use with dct:format)
  16. Archive Development • http://dublincore.org/documents/dcmi-terms/ • DCMI Metadata Terms • http://www.w3.org/2003/12/exif/

    • Exif RDF Schema • http://dublincore.org/documents/dcmi-terms/ • DCMI Metadata Terms • http://www.w3.org/2003/01/geo/ • Basic geo (WGS84 lat/long) Vocabulary
  17. Archive Development • http://creativecommons.org/ns • Creative Commons Rights Expression Language

    • http://sw.deri.org/2007/07/sitemapextension/ • Semantic Web Crawling: A Sitemap Extension