This document describes the Open Annotation Collaboration, which aims to create interoperable sharing of annotations on the web. It discusses the motivation to apply web standards to annotations to allow scholars to access their annotations from different tools. It outlines the Open Annotation data model, which defines annotations as having a body, target, and optional additional properties. The model supports various annotation types and ways to represent segments of resources. The collaboration seeks to build on this model to cover complex scholarly use cases while ensuring annotations are shareable across environments.

1. Open Annotation:
Annotating Scholarly Communication on the Web
Robert Sanderson
rsanderson@lanl.gov
Los Alamos National Laboratory
@azaroth42
Herbert Van de Sompel
herbertv@lanl.gov
Los Alamos National Laboratory
@hvdsomp
http://www.openannotation.org/
This research is funded, in part, by the
Andrew W. Mellon Foundation
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2. Overview
• Motivation
• Open Annotation Model
• Basics
• Segments
• Resources Changing over Time
• Machine Annotations
• Network Model
• Quick Demo
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3. Scholarly Communication
Scholarly Communication is increasingly:
• Online
• Open
• Distributed
• Collaborative
• Data-Oriented
Annotation is a scholarly primitive, spanning discipline and level.
Need to ensure that Digital Annotations fall under these headings!
• Apply the standards and architecture of the World Wide Web to the
Annotation use case.
• Even if scholar doesn’t share annotations with others, she will want
to access them from different tools and environments.
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4. Open Annotation Collaboration
http://www.openannotation.org/
Focus on interoperable sharing of annotations
• Web-centric and open, not locked down silos
• Create, consume and interact in different environments
• Build from a simple model for simple cases,
to more detailed for complex scholarly annotation requirements
The Collaboration:
• Los Alamos National Laboratory
• University of Illinois at Urbana-Champaign
• University of Queensland
• University of Maryland
• George Mason University
• … plus many adopters and partners
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5. Open Annotation Data Model
Design Guidelines:
• Based on the Architecture of the World Wide Web
• … and on Linked Open Data
• Should be general enough for ease of adoption
• … and rich enough to cover scholarly use cases
Status: Beta, with 9 ongoing funded experiments to inform 1.0
Hardest part: Define what an Annotation is!
• "Aboutness" is key to distinguish from general metadata
A document that describes how one resource is about
one or more other resources, or part(s) thereof.
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6. Basic Model
The basic model has three resources:
• Annotation (an RDF document)
• Body (the ‘comment’ of the annotation)
• Target (the resource the Body is ‘about’)
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7. Basic Model Example
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8. Additional Relationships and Properties
Any of the resources can have additional information attached,
such as creator, date of creation, title, etc.
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9. Additional Properties Example
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10. Annotation Types
There can be further types of Annotation, such as a Reply.
Example: Replies are Annotations on Annotations.
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11. Annotation Types Example
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12. Inline Information
It is important to be able to have content contained within the
Annotation document for Client Autonomy:
• Clients may be unable to mint new URIs for every resource
• Clients may wish to transmit only a single document
• Third parties can generate new URIs if the client does not
The W3C has a Content in RDF specification:
• http://www.w3.org/TR/Content-in-RDF10/
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13. Inline Information: Body
• We introduce a resource identified by a non resolvable URI,
such as a UUID URN, as the Body.
• We then embed the data within the Annotation document using
'chars’ from Content in RDF.
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14. Inline Body Example
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15. Multiple Targets
There are many use cases for multiple targets for an Annotation:
• Comparison of two or more resources
• Making a statement that applies to all of the resources
• Making a statement about multiple parts of a resource
The OAC Data Model allows for multiple targets by simply having
more than one hasTarget relationship.
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16. Multiple Targets Example
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17. Segments of Resources
Most annotations are about part of a resource
Different segments for different media types:
• Text: paragraph, arbitrary span of words
• Image: rectangular or arbitrary shaped area
• Audio: start and end time points, track name/number
• Video: area and time points
• Other: slice of a data set, volume in a 3d object, …
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18. Segments of Resources
Web Architecture Segmentation:
• A URI with a Fragment identifies part of the resource:
• IETF Mime-type fragment identifiers; eg xpointer
• W3C Media Fragments URI specification for simple
segments of media: http://www.w3.org/TR/media-frags/
We introduce a method of constraining resources:
• Introduce an approach for arbitrarily complex segments that
cannot be expressed using Fragments
• Can be applied to Body or Target resource
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19. Segments of Resources: IETF Fragment URIs
URI Fragments are a syntax for creating subsidiary URIs that
identify part of the main resource
The syntax is defined per media type:
• X/HTML: The named anchor or identified element
• XML: An XPointer to the element(s)
• PDF: Many options, especially page and viewrect
• Plain Text: Either by character position or line position
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20. Segments of Resources: W3C Media Fragments
Media Fragments allow anyone to create URIs that identify part of
an image, audio or video resource.
The most common case is for rectangular areas of images:
• http://www.example.org/image.jpg#xywh=50,100,640,480
Link to the full resource as well, for all Fragment URIs
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21. Media Fragments Example
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22. Complex Constraints
Fragment URIs are not always possible
• Introduce a Constraint that describes the segment of interest
• And a ConstrainedTarget that identifies the segment of interest
• Constraints are entire resources, so can be more expressive
• Constraints may also describe 'contextual' information
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23. Constraint Example
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24. Constrained Body
The Body may also be constrained in the same way as Targets
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25. Web-Centric Annotation: No Persistence
Google Sidewiki Annotation on http://news.bbc.co.uk/ as of 2010-06-14
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26. Web-Centric Annotation: No Annotations
Archived page from:
http://www.dracos.co.uk/work/bbc-news-archive/2010/03/08/07.05.html
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27. Web-Centric Annotation: Desired Cross-Linking
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28. Annotations and Time
There are three different types of Annotation with respect to Time:
• Timeless Annotations
• These are always relevant, regardless of the current
state of the resources. This is the base model.
• Uniform Annotations
• There is a single timestamp at which all of the resources
should be considered.
• Varied Annotations
• Each of the resources (Body, Targets) should be
considered at a different time.
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29. Uniform Annotations
If the same time is applicable to all resources, we attach it to the
Annotation using the oac:when predicate.
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30. Uniform Annotation Example
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31. Varied Annotations
If different timestamps are required for each resource, we use
oac:when from an oac:WebTimeConstraint.
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32. Varied Annotation Example
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33. Finding Archived Resources with Memento
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34. Annotations for/by Machines?
• The Body consists of one or more Statements
• Human understandable: Text, Image, Video, Symbols, …
• Machine understandable: Data
• Humans can infer relationships and context, Machines cannot
• Need to be as explicit as possible
• Need structured information
• When would we do this?
• Attaching data to another resource
• Nano-Publications: publication of data for further processing
• Semantic Annotations
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35. Semantic Annotation: Single Named Entity
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36. Semantic Annotation: Entity Relationships
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37. Advantages of this Approach
• Only uses existing OAC constructions
• No new ‘isTopicOf’ or similar shortcut relationships
• Creator of Body is not confused with Creator of Annotation!
• Aligns very closely with human annotation practices
• Consistent model that scales from resource to part of resource
• Can annotate data extracted at most appropriate level
• Could extract from sentence/paragraph/section/entire text
• Consistent model that allows association of any amount of data:
• From Single Entity
• To scholarly discourse extraction from entire document
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38. Annotation Protocols
Unlike previous systems, Open
Annotation does not mandate a
protocol.
No reliance on a client/server
combination gives the client
autonomy.
Instead we promote a publish/
subscribe methodology, where
annotations may be stored and
consumed from anywhere.
Protocol: publish, subscribe, consume tied together
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39. Publish/Subscribe Method
We don’t specify how this transfer should occur
publish
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40. Publish/Subscribe Method
Nor this.
publish subscribe
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41. Publish/Subscribe Method
Nor this.
publish subscribe consume
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42. Publish/Subscribe Advantages
• Client can use most appropriate method for transferring annotation to
storage service
• May already be specified in certain domains
• Can use existing services without requiring direct adoption
• Annotations are web resources in their own right
• Can be protected for limited access using existing technology
• Have their own URIs by necessity, not good-will of service
• Promotes a market-place of services
• Archiving Annotations and resources for preservation
• Enriching with additional metadata and information
• Aggregation and curation to provide trusted annotation feeds
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43. Demo!
http://www.shared-canvas.org/impl/demo3/
• Took the PDF of Dirac’s thesis on Quantum Mechanics and split into
individual page images
• Allow transcription by annotation, and commentary by annotation
• Allows storage at different services, both public and private
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44. Thank You
Robert Sanderson
rsanderson@lanl.gov
azaroth42@gmail.com
@azaroth42
Web: http://www.openannotation.org/
Paper: http://arxiv.org/abs/1003.2643
Slides: http://slidesha.re/qolpwI
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