The Open Annotation Collaboration (OAC) Model

MMWeb 2011 Workshop | Graz, Austria | Sept. 8th, 2011

The Open Annotation Collaboration (OAC) ModelBernhard 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


Overview

• Motivation and Goals

• The Open Annotation Data Model

• Status and Next Steps

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

http://www.openannotation.org/documents/AndyAshtonOACWorkshop.pdf


Annotation Supporting Collaborative Development of Scholarly EditionsAnna Gerber, Jane Hunter

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(c) Anna Gerber, Jane Hunter, Univ. Queensland (http://www.openannotation.org/documents/GerberHunterOAC.pdf)




“Annotation”

“An annotation associates one piece of information with one (or more) otherpiece(s) of information.”


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


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


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


Why not Annotea?

• Various Annotea extensions were defined throughout the years

• OAC tries to pull together various extensions of Annotea into a cohesive whole


Overview





Baseline ModelAn 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.

B-1 T-1

A-1

oac:hasBody oac:hasTarget

oac:Annotation

rdf:type


Baseline Model

ex:Anno


oac:Annotation


SerializationDereferencing the Annotation HTTP URI results in an RDF serialization of an instance of this data model.

ex:Anno


(rdf)HTTP GET


Additional Information

B-1 T-1

A-1


datetime dcterms:created

dcterms:creatorU-1

stringdc:titlestring

foaf:name

string

foaf:mbox

Additional properties and relationships can be associated with an Annotation.


Annotation Types

S-1 T-1

A-1


S-2

A-2


oac:Reply

oac:Annotation

rdf:type

rdf:type

oac:Annotation is the base class for Annotations. There can be more specialized types.


Inline Information

ex:Anno


This image is very

impressive!

ex:HDFI-1

UTF-8

cnt:charscnt:characterEncoding

ex:uuid

cnt:ContentAs

Text

rdf:type

Bodies can be embedded into the Annotation document by assigning a unique non-resolvable URN as identifier to the Body.


Fragment URIsThe user agent must be able to select part of the resource as the Body or Target for an Annotation, not just the entire resource.

http://www.example.net/foo.html#namedSectionhttp://www.example.net/foo.pdf#page=10&viewrect=20,100,50,60http://www.example.org/foo.txt#line=1,5http://www.example.net/foo.xml#xpointer(/a/b/c)

B-1 T-1#xy

A-1


T-1

dcterms:isPartOf


Media Fragment URIsThe W3C Media Fragment URI specification allows the creation of a URI that identifies a segment of image, video and audio resources.

ex:Anno


ex:HDFI-1#xywh=50,100,640,480tw:6312261983

dcterms:isPartOf

ex:HDFI-1


Constrained TargetsFor resource segments which cannot be described by (media) fragment URIs, we introduce ConstrainedTarget resources.

uu1

ex:Anno


describes

ex:svgc

ex:HDFI-1

tw:6312261983

image/svg+xml

dc:format

oac:constrainsoac:constrainedBy

(svg)

HTTP GET

oac:SvgConstraint

rdf:type


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


Uniform Time Annotation

ex:Anno

oac:hasBody oac:hasTargettw:11002497449

2010-03-2215:05:00 GMT

oac:when

ex:cnn


Overview





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)

• ....


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/

http://www.openannotation.org

http://www.openannotation.org







Education

The Open Annotation Collaboration (OAC) Model