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Re: Annotation protocol (creating a new annotation)

From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Date: Mon, 2 Feb 2015 23:22:06 +0000
Message-ID: <CAPRnXt=r4tmcjDkQEsU0cEWazF6wpuENrp4cw-Xm1Tp9+bPOVg@mail.gmail.com>
To: "Denenberg, Ray" <rden@loc.gov>
Cc: Web Annotation <public-annotation@w3.org>
We have not so far gone much into how to discover annotation
containers, or to place notifications that a resource has been

A brief touch on this is at

with the suggestion of a .well-known/ URI for annotations
(.well-known/annotations ?)

So in a way the applications "just has to know" - e.g. be configured
for it. xyz would never realize about the annotation unless it also
knows your server. (or it has a .well-known/annotations that you also

For the WG - it might  be worth looking at how PROV specified "ping
backs" and discovery mechanisms:


Discovery of a Provenance resource/service:

1) by a Link: header

2) By a <link> element in HTML5

3) By a property in RDF

I believe a similar pattern should work well also for annotations.

In PROV-AQ we split between provenance resource (a document that
contains provenance about the linked from resource) and provenance
query service (e.g. a SPARQL endpoint that contains provenance
"around" the resource).

I am not sure if we want to keep a similar split - e.g. a HTML
document could Link to some annotations, or alternatively to an
annotation service (where further annotations can be located and/or
created).  As annotations are generally made AFTER the document, I
would expect the first variant to be slightly less useful (harder to
maintain/dynamically generate) - although it does mean you can expose
annotations without setting up any special annotation servers.
Using JSON-LD or RDFa it is also easy to include such links within a
HTML-listing like "Comments".

For PROV, a ping-back service was described as a special kind of Link,
which is how one provenance service can let another one know that some
provenance has been created:


Basically here the provenance server POST to the linked service with URIs of
its provenance.

A similar pattern should work well also for annotations - so that xyz
can be told about myserver's annotations about xyz and something else.

myserver would POSTing URIs to the annotation service at xyz - which
then MAY go have a look around to see if it wants to aggregate those
external annotations somehow.

(NOTE: security considerations in such a scenario!
http://www.w3.org/TR/prov-aq/#security-considerations )

On 2 February 2015 at 22:40, Denenberg, Ray <rden@loc.gov> wrote:
> I’m trying to work through the protocol and I can see I’m going to have
> questions. I’ll start with the following, and the answer will probably lead
> to more questions.
> on server   xyz.org     there is resource R:
> http:/www.xyz.org/resources/resourceR
> On MY server:   http://www.ray.org/
> I create a review of resource R:
> http://www.ray.org/reviews/reviewOfResourceR
> I create an annotation:
> <http://www.ray.org/annotations/annotationForTheReviewOfResourceR>   a
> oa:Annotation ;
>                 oa:hasBody
> <http://www.ray.org/reviews/reviewOfResourceR>  ;
>                 oa:hasTarget                      <
> http:/www.xyz.org/resources/resourceR> .
> http://w3c.github.io/web-annotation/protocol/wd/   says
> “3.2.1 Create a New Annotation
> New Annotations are created by posting the JSON-LD serialization to an
> Annotation Container.”
> Annotation container where?  On  which server,  xyz or ray?   I assume “ray”
> because that’s my server so I know where the annotation container is, while
> I have no idea where the container is on xyz.
> My question is, how is server xyz made aware of the existence of this
> annotation?   Either I’m missing something, or the document hasn’t gotten
> that far yet.  If it’s the latter, fine, I just want to be sure I’m not
> missing something.
> Thanks.
> Ray

Stian Soiland-Reyes, eScience Lab
School of Computer Science
The University of Manchester
http://soiland-reyes.com/stian/work/    http://orcid.org/0000-0001-9842-9718
Received on Monday, 2 February 2015 23:22:55 UTC

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