The document discusses the Europeana object model and metadata. It describes how Europeana surrogates and semantic nodes represent real world objects and events. The draft model provides a "EuropeanaObject" class to represent these. Complex objects like books, exhibitions, and archival documents were also discussed. Basic relationships between objects like "is-part-of" and "is-derived-from" were identified. Implementation approaches like allowing all provider relationships or defining a small set of generalized ones were considered. Next steps include a Work Group report in April and initial specifications in May.

1. WG3.1 Object Model and
Metadata
Work Group Session 2, 3 April 2009

2. Object Model
•Europeana surrogates and semantic nodes are all
representations of things in the real world, both are
subclasses of higher class “EuropeanaObject”
•Discussion whether Events are like physical and digital
objects and therefore need Surrogate, or are like semantic
nodes providing context to objects
•Membership of a class depends on the properties and
relationships, so this needs to be analysed for Events
•First draft of Europeana model provided by Paolo Manghi
(next slide)

3. First draft of model

4. Complex Objects and Relationships
•Types of complex objects to be taken into account include:
• CDs with musical works, concerts, books and pages, sets of
archival documents, art works or specimens in exhibition
•Need for generalization of specific relationships but find
appropriate balance between:
• General enough to make sense to non-specialist user
• Specific enough not to alienate provider (domain specialist)
•Three (basic?) relationships identified:
• Is-part-of (unordered set): items in archive file, exhibition
• Is-part-of (ordered set): pages in book, items in news broadcast
• Is-derived-from: adaptations, translations, versions etc.

5. Some implementation issues
•Possible implementation approaches:
• Either allow for all specialized relationships from source metadata
in the model and combine into smaller set of general relationships
for search and navigation
• Or only define a small set of generalized relationships in the model
and map during ingestion process
•May need prototyping to verify performance and scalability
•In any case it may be wise to keep the original metadata
received from provider/aggregator so there is no need to go
back to provider if model changes – OAI-PMH should take
care of updates to metadata

6. Next steps
•Work Group 3.1 report to be available by mid-April
•First version of specifications scheduled for end of May: to
be shared with the Work Groups for feedback
•Final version of specifications scheduled for September: to
be presented at next meeting 14-16 September

7. Next steps
•Work Group 3.1 report to be available by mid-April
•First version of specifications scheduled for end of May: to
be shared with the Work Groups for feedback
•Final version of specifications scheduled for September: to
be presented at next meeting 14-16 September