The document summarizes the Open Annotation Collaboration (OAC) Model which aims to enable sharing of annotations across platforms and content collections. It presents the OAC goals, the baseline data model where an annotation associates a body resource about a target resource, additional properties that can be included, different annotation types, how bodies can be embedded inline, and how fragments and media fragments can identify portions of resources. It discusses how constrained targets can describe segments that can't use fragment URIs.

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