Slides from NISO meetings on Annotation in Frankfurt and San Francisco in October 2011

1. Open Annotation:
Social Bookmarking and Annotation of eBooks
Robert Sanderson
rsanderson@lanl.gov
Los Alamos National Laboratory
Todd Carpenter
National Information Standards Organization
Peter Brantley
Internet Archive
http://www.openannotation.org/
This research is funded in part by the Andrew
W. Mellon Foundation
Open Annotation Overview 1
San Francisco, 26th of October 2011

2. Overview
• Introduction
• Open Annotation Model
• Basics
• Segments
• Publish/Subscribe Model
• Appendix: FAQ
Open Annotation Overview 2
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3. Open Annotation Collaboration
• Focus on interoperable sharing of annotations:
• Web-centric and open, not application specific silos
• Create, consume and interact in different environments
• Build from a simple model for simple cases,
to more detailed for complex requirements
• Need for standards across platforms:
• Many people will want to share annotations and highlights
• Even if a reader doesn’t share her annotations with others,
she will want to access them from different reading apps
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4. 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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5. Basic Model Example
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6. 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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7. 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: image, audio, video
OAC introduces a method of constraining resources:
• Introduce an approach for arbitrarily complex segments
• Can be applied to Body or Target resource
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8. Complex Constraints
Fragments are often not possible:
• Introduce a Constraint that describes the segment of interest
• And a ConstrainedTarget that identifies the segment of interest
• Constraints are resources, so can be expressive and detailed
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9. Constraint Example
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10. Annotation Protocols
Unlike previous systems, Open
Annotation does not mandate a
protocol.
No reliance on a client/server
combination gives the client
autonomy to use different services
as appropriate.
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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11. Publish/Subscribe Method
We don’t specify how this transfer should occur
publish
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12. Publish/Subscribe Method
Nor this.
publish subscribe
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13. Publish/Subscribe Method
Nor this.
publish subscribe consume
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14. Publish/Subscribe Advantages
• Client can use most appropriate method for transferring annotation to
storage service
• May already be mandated in different domains
• Can use existing services without requiring them to change
• Annotations are web resources in their own right
• Can be protected for restricted access using existing technology
• Have their own URIs for identity
• Promotes a market-place of services, such as:
• Archiving Annotations and resources for preservation
• Enriching with additional metadata and information
• Spam detection and filtering to provide trusted annotation feeds
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15. OAC for eBooks: Open Questions
• Need to have robust mechanism for determining the segment of
interest:
• Could be part of an image
• Could be part of stable layout text
• Could be part of reflowable text
• Distrust of quoting passages: enough annotations and entire text
is unprotected
• Distrust of offsets: change in the text and Constraint will describe
the wrong segment
• Motivating public, rather than private, annotations is important
• … As is filtering spam!
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16. http://www.openannotation.org/
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17. FAQ
• Surely there's more to the model?
• What about creator, modification time and so on?
• I want to comment on an Annotation?
• I want to annotate multiple parts at once?
• How can the comment be part of the Annotation?
• You mentioned URI Fragments?
• How can my comment be part of another resource?
• I want to use quoted passages, but not still protect the quotes?
• I want to use character offsets, but know if the segment has changed?
• What about highlighting with no comment?
• What about different colors and styles of highlight?
• What about just marking a location, like a bookmark?
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18. What about Creator, Modification Time?
Any of the resources can have additional information attached,
such as creator, date of creation, title, etc.
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19. Additional Properties Example
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20. I Want to Comment on an Annotation?
There can be further typing of the Annotation to clarify purpose.
Example: Replies are Annotations on Annotations.
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21. Annotation Types Example
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22. I Want to Annotate Multiple Parts at Once?
Many use cases for multiple targets for a single 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
Enabled by allowing more than one hasTarget relationship.
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23. Multiple Targets Example
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24. How can the Comment be part of the Annotation?
Content may be contained within the Annotation document:
• Important 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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25. Inline Body
• Introduce a resource identified by a non resolvable URI
(such as a UUID URN) as the Body.
• Embed the data within the Annotation document using 'chars’
from Content in RDF.
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26. Inline Body Example
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27. You Mentioned URI Fragments?
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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28. 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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29. Media Fragments Example
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30. How can my Comment be Part of another Resource?
The Body may also be constrained in the same way as Targets.
(the most complicated OAC data model diagram)
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31. Constrained Body Example
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32. I Want to use Quoted Passages, but Protect the Text?
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33. I Want to use Offsets, but Know if the Text has Changed?
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34. What about Highlighting with No Comment?
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35. What about Highlighting with different Colors?
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36. What about just Bookmarking a Location?
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