Presented at iAnnotate16 (http://iannotate.org/) Cultural heritage institutions are looking at crowdsourcing as a new way and opportunity to improve the overall quality of their data and contribute to a better semantic description and link to the web of data. This is also the case for Europeana, as crowdsourcing under the form of annotations is envisioned and being worked on in several projects. As part of the EU Europeana Sounds project (http://www.europeanasounds.eu/), we have identified the user stories and requirements that cover the following annotation scenarios: open and controlled tagging; geotagging, enrichment of metadata; annotation of media resources; linking to other objects; moderation and general discussions. As a central point on all the efforts around annotations is an agreement on how these should be modelled in a uniform way for all these scenarios, as it is essential to bring such information to Europeana and in a way that can also be easily exploited and shared beyond our portal. For this, we are using the recent W3C Web Annotation Data Model (WADM) supported by the Open Annotation community as it is the most promising model at the moment. Due to its flexible design and early stage of development, at the moment, there is insufficient recommendations on how some of our user stories and requirements can be modelled. In our presentation we will make proposals on how the WADM can be applied for these scenarios and we are looking for discussion/feedback from the community in the hope that it will help cultural heritage institutions and other communities to better understand how annotations can be modelled.

1. Challenges on modeling annotations
in the Europeana Sounds project
Hugo Manguinhas, Sergiu Gordea, Antoine Isaac, Alessio Piccioli,
Giulio Andreini, Francesca Di Donato, Remy Gardien, Maarten
Brinkerink | iAnnotate 2016

2. What is Europeana?
Challenges on modeling annotations in the Europeana Sounds project
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We aggregate metadata:
• From all EU countries
• 3,500 galleries, libraries,
archives and museums
• More than 52M objects
• In about 50 languages
Europeana aggregation infrastructure
Europeana| CC BY-SA
The Platform for Europe’s Digital Cultural Heritage

3. Why are annotations useful?
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For Users, a means to…
• Contribute with their knowledge
• Discuss and share their knowledge with others
For Cultural Institutions, a new way and opportunity to
increase the quality of their metadata
• Improve consistency
• Contribute to a better semantic description, with internal cross-
linking and links to the web of data
Challenges on modeling annotations in the Europeana Sounds project

4. The Europeana Sounds project
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Europeana Sounds aims to increase the amount of audio
content available via Europeana
• also improving geographical and thematic coverage
Apart from aggregation, it improves discovery and use of
audio content, by enriching metadata through innovative
methods
Challenges on modeling annotations in the Europeana Sounds project

5. Annotation Scenarios in Europeana Sounds
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A user annotates a Cultural Heritage Object, in particular…
• Information describing the object (i.e. metadata)
• Contextual information (i.e. metadata about Agents, Places, Subjects, … )
• Media resources representing the object
By the following actions:
• Tag with terms from controlled vocabularies
• Complete or correct information
• Favour or moderate annotations made by other users
• Comment and discuss with other users
• Relate objects together
Challenges on modeling annotations in the Europeana Sounds project

6. Crowdsourcing Infrastructure
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Challenges on modeling annotations in the Europeana Sounds project
Annotation Providers
Annotation Client
TheSession.org + TunePal HistoryPin.org Pundit WITH

7. Exchanging annotations across platforms
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We adopted the W3C Web Annotation Data Model
• Offers a simple model for exchanging annotations across platforms
... but flexible enough to support complex scenarios
We are developing a REST API based on the W3C Web Annotation
Protocol
• Which developers & Europeana will use for retrieval, creation and
search of annotations
Challenges on modeling annotations in the Europeana Sounds project

8. Tagging with semantic resources
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User scenario:
A end-user wishes to tag a
Europeana object using a
term/resource from a
controlled vocabulary
Challenges on modeling annotations in the Europeana Sounds project
Item as displayed in the
Europeana Collections Portal

9. Tagging with semantic resources
The Pundit use case
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Challenges on modeling annotations in the Europeana Sounds project
DBpedia
API
oa:Annotation
http://data.europeana.eu/an
notation/...
oa:hasBody
skos:Concept
http://dbpedia.org/resource/
Brass_instrument
oa:tagging
oa:motivatedBy
edm:ProvidedCHO
http://data.europeana.eu/item/09102/_UEDIN_214
oa:hasTarget
Available
Vocabularies
/ Datasets

10. Tagging with semantic resources
Open Questions
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… some aspects may significantly influence user experience:
• Should different kinds of semantic resources be displayed in the
same way? ...or should they be differentiated by type (ie. a Place vs Agent)
or scope (e.g. Rock as a sound genre vs a physical thing).
• Which label(s) should be displayed? Should the one that best fits the
display settings (ie. language preferences) be used - what if no label
exists for that language?
• Should the user annotate with any term from a vocabulary, or only
a subset?
• What to do with annotations when a vocabulary is updated by its
maintainer?
Challenges on modeling annotations in the Europeana Sounds project

11. Tagging with semantic resources
Challenges
Client applications must:
• have all data necessary for feeding the display and
• in an way that they can uniformly process
This means that resources must be:
• Dereferenced
• Translated into an uniform data format
To tackle these challenges we chose the Europeana Data Model:
• Already in use at Europeana
• Reuses existing standards (e.g. SKOS, DublinCore, WGS84 Geo Positioning)
• Gives support for all contextual resources
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Challenges on modeling annotations in the Europeana Sounds project

12. Tagging with geographical information
The HistoryPin.org use case
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Challenges on modeling annotations in the Europeana Sounds project
User can specify the rough
coordinates and a radius
An Europeana Object displayed in
HistoryPin.org

13. Tagging with geographical information
The HistoryPin.org use case
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Challenges on modeling annotations in the Europeana Sounds project
{
"@context": "http://www.w3.org/ns/anno.jsonld",
"id": "http://data.europeana.eu/annotations/historypin/136290",
...
[provenance info here],
...
"motivation": "tagging",
"body": {
"@context": <Context for EDM>,
"type": "edm:Place",
"wgs84_pos:lat": "48.85341",
"wgs84_pos:long": "2.3488"
},
"target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}
Similar as semantic tagging but
using a “virtual” resource
Coordinates expressed using
WGS84 Geo Positioning

14. Annotating metadata
The Pundit use case
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We consider metadata annotations as…
• any annotation that refers to or asserts a statement to the
information describing an object in order to complete or correct it
Ideally, and like other annotations, they should be
• agnostic to the way they are presented to the user in the interface
• machine readable
So that metadata annotations can
• survive changes to the interface design;
• allow them to be easily shared outside the interface they were
originally created;
• allow for other software applications to take further advantage of it
Challenges on modeling annotations in the Europeana Sounds project

15. Annotating metadata
A Proposal
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Challenges on modeling annotations in the Europeana Sounds project
oa:Annotation
http://data.europeana.e
u/annotation/...
oa:describing?
oa:motivatedBy
pundit:MetadataSelector
#statement1
oa:SpecificResource
#metadata1
oa:hasTarget
oa:hasSelector
rdf:predicate
Graph
Correct URI
edm:ProvidedCHO
http://data.europeana.eu/item/09102/_UEDIN_214
dcterms:isPartOf
oa:hasSource
rdf:value
oa:hasBody
A specific
motivation may be
needed
Similar to a
rdf:Statement but
following WA guidelines

16. Favouring and moderating annotations
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As manual per-annotation moderation does not scale well,
we wish to encourage a crowd-moderation policy among the
end-users:
• Three-strikes-out: if three users report an annotation as
in violation of the terms of use, it will be hidden.
How to differentiate moderation (violations of terms of use) from
up- and down-voting ('this is a very good annotation, +1')?
Challenges on modeling annotations in the Europeana Sounds project

17. Conclusion
• Requirements are becoming clearer as we work on more
concrete use-cases and validate them with real users
• Expressing cross-platform annotations in an uniform way is a
big challenge:
• W3C Web Annotation Data Model gives a good interoperable
base
• But, not all scenarios are yet covered
• Need for best practices for specific applications / domains
• Still a lot of work ahead...
...but we are making progress
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Challenges on modeling annotations in the Europeana Sounds project

18. http://www.europeanasounds.eu/