RE: Annotate same text fragment.



4.1 of the Web Annotation Data Model notes


1.       If a Specifier (e.g., an oa:Selector) "has an HTTP URI, then its description, and only its description, must be returned when the URI is dereferenced."

2.       But if an oa:SpecificResource "has an HTTP URI, then the exact segment of the Source resource that it identifies, and only the segment, must be returned when the URI is dereferenced."


I take this to mean that if I am using an oa:SpecificResource to target a text fragment as my Annotation Target, I should give it a URI only if I have a service that will deliver that exact text fragment when the URI is de-referenced. Otherwise I should give a URI to the description (e.g., in JSON) of the Selector and then reuse that to construct a new blank node oa:SpecificResource in each subsequent Annotation that wants to target the same text fragment.  


First, is this the correct interpretation?


Second, if so this is mildly inconvenient. Can you remind me as to the rationale for doing this (e.g., as opposed to allowing a redirection to an RDF description of the SpecificResource Target as an option)?




Tim Cole



From: Susanna Netseven [] 
Sent: Friday, May 29, 2015 3:09 AM
To: Robert Sanderson <>
Cc: Annotation WG <>
Subject: Re: Annotate same text fragment.



Usually we use Target as oa:SpecificResource cause we need to annotate partial text or partial images. 

We think this way will permit in future to have informations about annotations that share the same text fragment. (eg. SPARQL interrogation)




On Thu, May 28, 2015 at 6:42 PM, Robert Sanderson < <> > wrote:


Thanks for the question Susanna.  Yes, that's correct -- you can reuse the Target IRIs when they're Specific Resources in the same way that you could reuse Target IRIs when they're web pages or other content.





On Thu, May 28, 2015 at 9:40 AM, Susanna Netseven < <> > wrote:

Hi, i have a technical question regarding a possible implementation about a typical use case we are facing.

I annotate a text fragment in html page, for example by commenting a text fragment with "this is incorrect"

In the RDF model we would  have:


<Annotation-IRI1> <oa:hasTarget> <Target-IRI1> 


and other target's predicates for selector for text-fragment, source and scope .


Then, another user wants to annotate the same text fragment. 
in this case the correct RDF should be as following?

<Annotation-IRI2> <oa:hasTarget> <Target-IRI1>

In this case we don't assume to create a new Target IRI but reuse the first.
Could be this a correct solution?




Rob Sanderson

Information Standards Advocate

Digital Library Systems and Services

Stanford, CA 94305


Received on Monday, 3 August 2015 21:43:20 UTC