Multiplicity and Publishing in Open Annotation (tutorial)

Open Annotation Data Model:
Multiplicity and Publishing Modules

Robert Sanderson
azaroth42@gmail.com
Los Alamos National Laboratory
@azaroth42

Paolo Ciccarese
paolo.ciccarese@gmail.com
Harvard Medical School
@paolociccarese

(Community Group Co-Chairs)

Open Annotation Community Group West Coast Open Annotation Rollout
http://www.w3.org/community/openannotation/ April 9th 2013, Stanford, CA, USA 1

Multiplicity

The Data Model allows for multiple bodies and multiple targets
•  Easiest: Multiple instances of hasBody, hasTarget
•  Issue: What are the semantics?

Multiples of hasBody/hasTarget: Treated individually

Requirements:
•  Choice: Only one resource needs to be displayed
•  Composite: All resources are required together, as a set
•  List: All resources are required together, with order


Multiplicity: Choice

Choice: Rendering agent should choose one resource to display
oa:default: The default resource of the Annotation’s producer
oa:item: Another possible resource


Multiplicity: Choice


Multiplicity: Composite

Composite: A set of resources, all of which are required to understand the
Annotation correctly


Multiplicity: Composite


Multiplicity: List


Publishing Annotations

The Data Model is only a model, not a protocol:
•  Does not specify interactions between client/server
•  Does not limit additional descriptive features
•  Does not specify annotation search, retrieval or management

Some aspects related to publishing are important:
•  Serialization of the model
•  Embedding resources
•  Including other graphs
•  Equivalence of resources


Publishing: JSON-LD Serialization

JSON-LD is the latest RDF serialization:
http://json-ld.org/spec/latest/json-ld/

Open Annotation recommends its use over RDF/XML:
•  Easier for developers
•  More web application friendly
•  Looks like JSON (with appropriate context)
•  So special parser not required
•  Easy to generate without special libraries

RDF/XML and Turtle are also recommended, if content negotiation is
supported.


Publishing: JSON-LD Context

JSON-LD has a Context description which maps JSON object keys to
RDF predicates, and assigns namespace prefixes:

{“@context”:{
“oa”: “http://www.w3.org/ns/oa#”,
“cnt”: “http://www.w3.org/2011/content#”,
“dc”: “http://purl.org/dc/elements/1.1/”,
…
“hasBody”: {“@type”:”@id”, “@id”:”oa:hasBody”},
“hasTarget”: {“@type”:”@id”, “@id”:”oa:hasTarget”},
…
“chars”: “cnt:chars”,
“format”: “dc:format”,
“when”: “oa:when”
…
}
}


Publishing: JSON-LD Example

Reuse of the Context definition makes simple annotations simple:

{
“@context”: “http://www.w3.org/ns/oa-context-20130208.json”,
“@type”: “oa:Annotation”,
“hasBody”: “http://www.youtube.com/watch?v=fgg2tpUVbXQ”,
”hasTarget”: ”http://zebu.uoregon.edu/hudf/hudf_300dpi.jpg”
}


Publishing: JSON-LD Example

And complex annotations still (somewhat) readable:

{
“@context”: “http://www.w3.org/ns/oa-context-20130208.json”,
“@id”: “http://www.example.org/annotations/1.json”,
“@type”: “oa:Annotation”,

“annotatedAt”: “2012-11-10T09:08:07”,
“annotatedBy”: {
“@id” : “http://www.example.com/people/rsanderson”,
“@type”: “foaf:Person”,
“mbox”: “rsanderson@example.com”},

“hasBody”: “http://www.youtube.com/watch?v=fgg2tpUVbXQ”,

…


Publishing: JSON-LD Example (cont)

”hasTarget”: {
”@id”: ”urn:uuid:1d823e02-60a1-47ae-bc872081729c”,
”@type”: ”oa:SpecificResource”,
”hasSelector”: {
”@id”: ”urn:uuid:6e353e12-30c2-98a3-39ff2081729c”,
”@type”: ”oa:FragmentSelector”,
”conformsTo”: ”http://www.w3.org/TR/media-frags”,
”value”: ”xywh=10,10,5,5”
}
”hasSource”: {
”@id”: ”http://zebu.uoregon.edu/hudf/hudf_300dpi.jpg”,
”@type”: ”dcterms:Image”
}
}


Publishing: Embedding Resources

Resources other than the body can benefit from being embedded:
•  SVG Selector
•  CSS Style

Potentially other resources:
•  When the resource is offline, and being sent along with the
annotation to a publishing server
•  For preservation
•  To include the exact representation, perhaps otherwise un-
obtainable


The Content in RDF specification is reused:


Publishing: Embedding RDF Graphs
It is useful to embed RDF graphs within the Annotation.
Prefer to use Content in RDF approach, but if Trig/Trix is requested:


Publishing: Embedding RDF Graphs


Publishing: Equivalent Resources
Useful to know that Annotations (and other resources) have been
duplicated between systems:


Publishing: Equivalent Resources


Extending Motivations
The Data Model defines only a few core Motivations

Intent is for communities to extend as necessary:
1.  Create a new ConceptScheme (vocabulary/taxonomy)
2.  Create a new instance of oa:Motivation
3.  Link new instance to at least one existing Motivation if possible
4.  Assign labels and other information to describe its use


Thank You

Robert Sanderson
azaroth42@gmail.com
Los Alamos National Laboratory
@azaroth42

Paolo Ciccarese
paolo.ciccarese@gmail.com
Harvard Medical School
@paolociccarese

(Community Group Co-Chairs)

http://www.flickr.com/photos/hinkeb/5232293964/

http://www.w3.org/community/openannotation/
http://www.openannotation.org/


Multiplicity and Publishing in Open Annotation (tutorial)

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Multiplicity and Publishing in Open Annotation (tutorial)

Similar to Multiplicity and Publishing in Open Annotation (tutorial) (20)

More from Robert Sanderson

More from Robert Sanderson (20)

Recently uploaded

Recently uploaded (20)

Multiplicity and Publishing in Open Annotation (tutorial)