Antoine Isaac 1 st PRELIDA Workshop Pisa, June 26, 2013

What is Europeana?

Europe’s digital cultural network Museums National Aggregators Regional Aggregators Archives Thematic collections Libraries 26M objects and 2,200 European galleries, museums, archives and libraries

What types of objects does Europeana gives access to? Video Text Image Video Sound 3D

What Europeana makes available Metadata Link to digital objects online

Metadata for re-use Available via  API  Search widgets  Experimenting with Linked Data CC

Europeana & Linked Open Data

New Europeana Data Model

A model for linking metadata Internal links and external links Representing better original metadata - reducing information loss Enabling metadata enrichment

Europeana and LD – a blurred picture Ingest metadata as XML (even though it is a form of RDF/XML) But able to fetch some linked data when using specific vocabularies Store in non-RDF store Yet do query expansion using semantic hierarchies or concepts with translated labels

Europeana and LD – a blurred picture Enrich metadata with linked data sources GEMET, Geonames, Dbpedia (a bit) Output metadata in Linked data ways Pilot “real” linked data – data.europeana.eu Schema.org mark-up on portal Soon JSON-LD for API results

Europeana (and friends) and preservation

Not very good Europeana metadata changes Europeana often re-ingest metadata Descriptions change: objects added or removed, mappings changed Europeana links die Two causes: Aggregation process (organization of data sources) sometimes result in a change of collection IDs – shared blame! Providers change their data, including their identifiers

The community doesn’t seem to care much Europeana Task force on persistent identifiers No result so far, except me giving some input to Phil… LODLAM session on preserving linked data last week in Montreal 4 participants There are more urgent problems to solve LD preservation issues seem similar to Web ones. And Web survive without apparently bothering…

And yet there are discussions (1/2) -Basic issue: preserving data for decentralized access and use -Basic requirement: persistent URIs -Beyond persistent URIs: data/links can change! -Updates are similar to what happens for historical place names in library catalogues -Importance of preserving contexts: different parts of the provenance (esp. data producers and time) -RDF triples make time and data provenance tricky, unless we go for quadruples or versioned URIs, making it more difficult for “basic” users -Interest of "historical Http GET”, à la Memento

And yet there are discussions (2/2) -Basic solution: no versioned URIs, but keep track of different versions of the representations Internet Archive with one canonical RDF representation for each URI -Preserve/give access to which versions of the data? - Users probably want the "best" data for a URI. And it may change… - Libraries have cases where people ask to remove data. An authoritative service should not serve historical data then. - Should we create/re-use URIs or HTTP status codes (410?) for removed data? Keep in mind: Cf OAIS, preservation success is success for humans!

Thank you Antoine Isaac - with slides from the Europeana Office