Navigation: (AmbraContentModel)

PubApp Annotation Content Model

Annotations are user made statements that consist of these main parts: the body of the annotation, which contains the textual or graphical content of the annotation, the link to the annotated document with a location within the document, an identification of the person making the annotation and additional metadata related to the annotation. We are going to leverage the work already done by various parties in this space, specially W3C. The standard we are going to use is defined by W3C as Annotea.

Annotea is part of the Semantic Web efforts. It provides a RDF metadata based extendible framework for rich communication about Web pages while offering a simple annotation and bookmark user interface. The annotation metadata can be stored locally or in one or more annotation servers and presented to the user by a client capable of understanding this metadata and capable of interacting with an annotation server with the HTTP service protocol. In Annotea, the metadata of an annotation is modeled according to an RDF schema and gives information such as the date of creation, name of the author, the annotation type (e.g., comment, query, correction...) the identifier of the annotated document, and an link that specifies what part of the document was annotated. The metadata also includes a pointer to the body of the annotation, which we assume to be structured based on the type of annotation. The annotation metadata does not say how the annotations must be presented to the user. This choice is left open to the developer of the client.

The annotation properties of Annotea in RDF are illustrated in the following figure:

The basic properties are in the Annotation namepsace http://www.w3.org/2000/10/annotation-ns# are:

rdf:type	An indication of the creator's intention when making an annotation; the value should be of rdf:type Annotation or any of its subclasses
annotates	The relation between an annotation resource and the resource to which the annotation applies
body	The content of the annotation
context	Context within the resource named in annotates to which the annotation most directly applies. This could be an XPointer. It may include a location range too.
author	The creator of the annotation (resource, probably foaf:person). Subclass of dc:creator
created	The date and time on which the annotation was created
modified	The date and time on which the annotation was last modified
supersedes	This predicate identifies the annotation that is supersedes. Used for versions
supersededBy	This predicate identifies the annotation supersedes it. Used for versions

The different types of annotations defined in http://www.w3.org/2000/10/annotationTypes# are:

Annotation	A super class describing the common features of annotations
Advice	A subclass of Annotation representing advice to the reader
Change	A subclass of Annotation describing annotations that document or propose a change to the source document
Comment	A subclass of Annotation describing annotations that are comments
Example	A subclass of Annotation representing examples
Explanation	A subclass of Annotation representing explanations of content
Question	A subclass of Annotation representing questions about the content
SeeAlso	A subclass of Annotation representing a reference to another resource

PubApp Annotations

Annotation

For the first release (Fall launch, 2006), we will support only Comment type of annotations. They might look something like:

<r:RDF xmlns:r="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:a="http://www.w3.org/2000/10/annotation-ns#"
  xmlns:d="http://purl.org/dc/elements/1.1/">

  <r:Description>
    <r:type resource="http://www.w3.org/2000/10/annotation-ns#Annotation"/>
    <r:type resource="http://www.w3.org/2000/10/annotationType#Comment"/>
    
    <a:annotates r:resource="http://example.com/some/page.html"/>

    <a:context>#xpointer(id("Main")/p[2])</a:context>

    <a:author r:resource="http://www.pone.org/users/#JoeSmith"/>

    <a:created>2004-10-14T12:10Z</a:created>

    <a:body r:resource="http://www.example.com/mycomment.html"/>
  </r:Description>
</r:RDF>

So the standard Annotea properties and their values in PubApp will be:

author	Will point to a resource which will be of type foaf:person
annotates	Will point to a URI identifying the object of interest
created	The date and time in yyyy-mm-ddThh:mm:ssZ format
body	Will point to a list resource which will contain the body(versions) of the annotation. See below
context	Contains the xpointer identifying the area within object of interest