1. The Open Annotation
Collaboration (OAC) Model
Bernhard Haslhofer | Cornell University / University of Vienna
Rainer Simon | Austrian Institute of Technology
Robert Sanderson | Los Alamos National Laboratory
Herbert van de Sompel | Los Alamos National Laboratory
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

2. Overview
• Motivation and Goals
• The Open Annotation Data Model
• Status and Next Steps
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

5. (c) Andy Ashton, Brown Digital Repository (http://www.openannotation.org/documents/AndyAshtonOACWorkshop.pdf)

6. !"#$%&'()!"%&#*#+,-.)/,+')0)1'%&.
Annotation Supporting Collaborative Development of Scholarly Editions
Anna Gerber, Jane Hunter
(c) Anna Gerber, Jane Hunter, Univ. Queensland (http://www.openannotation.org/documents/GerberHunterOAC.pdf)

7. “Annotation”
“An annotation associates one piece of
information with one (or more) other
piece(s) of information.”
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

8. Current Annotations
• are stuck in silos
• consumable only by a single client
• not sharable beyond original environment
• are repository-centric, not Web-centric
• no first class resources
• no global identifiers
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

9. OAC Goals
• Enable sharing of annotations across
clients, platforms and content collections
• Re-think annotations in terms of the Web
• Adopt Linked Data ideas for annotations
• Primary focus on scholarly annotations
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

10. Why not Annotea?
• Annotea (2001)
• designed for the annotation of Web pages
not for multimedia Web resources
• defines an Annotea-specific protocol
• no time dimension
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

11. Why not Annotea?
• Various Annotea extensions were defined
throughout the years
• OAC tries to pull together various
extensions of Annotea into a cohesive
whole
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

12. Overview
• Motivation and Goals
• The Open Annotation Data Model
• Status and Next Steps
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

13. Baseline Model
An Annotation is a document identified by an HTTP URI and describes
an association created between a Body resource and a Target
resource. The Body must be somehow about the target.
oac:
Annotation
rdf:type
A-1
oac:hasBody oac:hasTarget
B-1 T-1
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

14. Baseline Model
oac:
Annotation
ex:
Anno
oac:hasBody oac:hasTarget
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

15. Serialization
Dereferencing the Annotation HTTP URI results in an RDF
serialization of an instance of this data model.
HTTP GET (rdf)
ex:
Anno
oac:hasBody oac:hasTarget
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

16. Additional Information
Additional properties and relationships can be associated with an
Annotation.
datetime dcterms:created dc:title string
string
foaf:name dcterms:creator A-1
U-1
oac:hasBody oac:hasTarget
foaf:mbox
B-1 T-1
string
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

17. Annotation Types
oac:Annotation is the base class for Annotations. There can be more
specialized types.
oac:
Reply
rdf:type
A-2
oac:
Annotation
oac:hasBody oac:hasTarget
rdf:type
S-2 A-1
oac:hasBody oac:hasTarget
S-1 T-1
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

18. Inline Information
Bodies can be embedded into the Annotation document by assigning a
unique non-resolvable URN as identifier to the Body.
cnt:
ContentAs ex:
Text Anno
oac:hasBody oac:hasTarget
rdf:type
ex:
uuid
cnt:characterEncoding cnt:chars
UTF-8 This image
is very
impressive!
ex:HDFI-1
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

19. Fragment URIs
The user agent must be able to select part of the resource as the Body
or Target for an Annotation, not just the entire resource.
A-1
oac:hasBody oac:hasTarget
T-1
B-1 T-1
#xy
dcterms:isPartOf
http://www.example.net/foo.html#namedSection
http://www.example.net/foo.pdf#page=10&viewrect=20,100,50,60
http://www.example.org/foo.txt#line=1,5
http://www.example.net/foo.xml#xpointer(/a/b/c)
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

20. Media Fragment URIs
The W3C Media Fragment URI specification allows the creation of a
URI that identifies a segment of image, video and audio resources.
dcterms:isPartOf
ex:HDFI-1
ex:
Anno
oac:hasBody oac:hasTarget
tw:6312261983 ex:HDFI-1#xywh=50,100,640,480
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

21. Constrained Targets
For resource segments which cannot be described by (media) fragment
URIs, we introduce ConstrainedTarget resources.
ex:
Anno
oac:hasBody oac:hasTarget
tw:6312261983
uu1
oac:constrainedBy
oac:constrains
ex:
image/
svgc
svg+xml
dc:format
describes
rdf:type
HTTP GET
oac:Svg
Constraint
(svg)
ex:HDFI-1
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

22. Time Dependent Annotations
• Resource representations change over time
• Three types of time dependent annotations
• Timeless Annotations
• Uniform Time Annotations
• Varied Time Annotations
• Distinction through use of oac:when
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

23. Uniform Time Annotation
ex:
oac:when
Anno
2010-03-22
15:05:00 GMT
oac:hasBody oac:hasTarget
tw:11002497449
ex:cnn
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

24. Overview
• Motivation and Goals
• The Open Annotation Data Model
• Status and Next Steps
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

26. Demonstration Experiments
• Annotation Supporting Collaborative Development of
Scholarly Editions (AustLit)
• Annotation of Digitized Medieval Manuscripts (Stanford)
• Annotation of Subscription Streaming Video Content
(Alexander Street Press)
• Annotation of Digital Emblematica (Emblematica Online)
• Annotation of Historic Maps (Cornell)
• ....
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

28. Further Infos / Resources
http://www.openannotation.org/
http://dme.ait.ac.at/annotation/
http://code.google.com/p/oac-js/
https://github.com/yuma-annotation/
MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011