Re: [model] Clarifying annotation architecture

(Coming late in the discussion, having been on vacations)


> On 23 Jul 2015, at 17:34 , Frederick Hirsch <w3c@fjhirsch.com> wrote:
> 
> (not as chair)
> 

And not as a staff contact:-)

> Rob
> 
> yes that helps quite a bit.
> 
> I still see a problem explaining to JSON (non-turtle, non-RDF, non-JSON-LD) people why what looks like straightforward JSON is wrong, since they don't care about SpecificResources and triples..
> 
> if there were no JSON-LD and no linked data, the following *would be fine* JSON, right?
> 
> {
>  "kind": "Annotation",
>  "target" : "some-uri.html",
>  "body": {
>    "source: "meme-image.jpg",
>    "role": "commenting"
>  }
> }
> 

Rob, why isn't this structure o.k.?

I have ran this through the JSON-LD playground (adding a prefix to the properties to avoid writing a separate context) and the result, in terms of N-Triples, is this:

_:b0 <o:body> _:b1 .
_:b0 <o:kind> "Annotation" .
_:b0 <o:target> "some-uri.html" .
_:b1 <o:role> "commenting" .
_:b1 <o:source> "meme-image.jpg" .

translated back into Turtle for readability:

_:b0
 <o:kind> "Annotation",
 <o:target> "some-uri.html",
 <o:body> [
  <o:role> "commenting",
  <o:source> "meme-image.jpg"
 ] .


The only difference I can see is that there is no explicit typing for SpecificResource. So what? Only RDF people really care about the exact typing, and if we define the vocabulary in such a way that the domain of "source" is SpecificResource, then we got it.

What do I miss?

Ivan

> This is why the problem is "non-obvious".
> 
> Is there a way to transform this via implementation to using SpecificResource by default? Did this come up in the JSON-LD discussions?
> 
> Does this make the issue clear from the JSON implementer point of view?
> 
> regards, Frederick
> 
> Frederick Hirsch
> 
> fjhirsch.com
> @fjhirsch
> 
> 
>> On Jul 23, 2015, at 11:02 AM, Robert Sanderson <azaroth42@gmail.com> wrote:
>> 
>> 
>> Sure!
>> 
>> Good:
>> 
>> _:anno a oa:Annotation ;
>>  oa:hasTarget <some-uri.html> ;
>>  oa:hasBody _:specres .
>> 
>> _:specres a oa:SpecificResource ;
>>  oa:motivatedBy oa:commenting ;
>>  oa:hasSource <meme-image.jpg> .
>> 
>> 
>> Bad:
>> 
>> _:anno a oa:Annotation ;
>>  oa:hasTarget <some-uri.html> ;
>>  oa:hasBody <meme-image.jpg> .
>> 
>> <meme-image.jpg> oa:motivatedBy oa:commenting .
>> 
>> 
>> (Or substitute some new predicate like oa:role or whatever, per Tim Cole's comment that specific resources aren't really motivated in the same way that annotations are)
>> 
>> Hope that helps :)
>> 
>> Rob
>> 
>> 
>> On Thu, Jul 23, 2015 at 7:58 AM, Denenberg, Ray <rden@loc.gov> wrote:
>> Rob – still trying to grasp this.  Could you show how this would look done the “right” way, I.e. as a specific resource,
>> 
>> 
>> 
>> AND   please write both (the bad example and the good)  in turtle, not json-ld.
>> 
>> 
>> 
>> Thanks.
>> 
>> 
>> 
>> Ray
>> 
>> 
>> 
>> 
>> 
>> From: Robert Sanderson [mailto:azaroth42@gmail.com]
>> Sent: Thursday, July 23, 2015 10:30 AM
>> To: Denenberg, Ray
>> Cc: Jacob Jett; Frederick Hirsch; W3C Public Annotation List
>> 
>> 
>> Subject: Re: [model] Clarifying annotation architecture
>> 
>> 
>> 
>> 
>> 
>> We shouldn't (must not) do this:
>> 
>> 
>> 
>> {
>> 
>>  "@type": "Annotation",
>> 
>>  "target" : "some-uri.html",
>> 
>>  "body": {
>> 
>>    "@id": "meme-image.jpg",
>> 
>>    "role": "commenting"
>> 
>>  }
>> 
>> }
>> 
>> 
>> 
>> As meme-image.jpg might have another role in a different annotation (replacing, in Doug's example)
>> 
>> 
>> 
>> Rob
>> 
>> 
>> 
>> 
>> 
>> On Thu, Jul 23, 2015 at 6:37 AM, Denenberg, Ray <rden@loc.gov> wrote:
>> 
>> Hi Jacob – No, I’m afraid I don’t see that the “sky colored red” example applies to my question, however, if you (or someone) could write, in RDF syntax, an example annotation, which does specifically what it is we are saying we shouldn’t do …  specifically: attach a motivation to a body  (and more specifically, where the body is an image or some other non-rdf resource) ... that would help.
>> 
>> Thanks.
>> 
>> 
>> 
>> Ray
>> 
>> 
>> 
>> From: jgjett@gmail.com [mailto:jgjett@gmail.com] On Behalf Of Jacob Jett
>> Sent: Wednesday, July 22, 2015 5:16 PM
>> To: Denenberg, Ray
>> Cc: Robert Sanderson; Frederick Hirsch; W3C Public Annotation List
>> 
>> 
>> Subject: Re: [model] Clarifying annotation architecture
>> 
>> 
>> 
>> Hi Ray,
>> 
>> 
>> 
>> This is a distinctly RDF thing. Essentially the triples are all distinct assertions.
>> 
>> 
>> 
>> Imagine that I told you, "the sky is red". In ttl we might write the assertion this way --
>> 
>>     Sky colored Red .
>> 
>> 
>> 
>> This statement is true at certain points in time. Unfortunately RDF does not have a way to scope the assertion to certain points in time (or in the roles example, specific contexts). So from the SemWeb perspective "Sky colored Red ." and "Sky colored Blue ." are both true at all times and in all places. Using the specific resource allows us to scope the assertions, e.g., Sky@time@place colored Red .
>> 
>> 
>> 
>> Is that example helpful at all?
>> 
>> 
>> 
>> I think Rob's suggestion is a reasonable work around for this role issue. It should be invisible to those who don't care about SemWeb issues and makes the data reasonably actionable for those who do.
>> 
>> 
>> 
>> Regards,
>> 
>> 
>> 
>> Jacob
>> 
>> 
>> 
>> 
>> 
>> _____________________________________________________
>> 
>> Jacob Jett
>> Research Assistant
>> Center for Informatics Research in Science and Scholarship
>> The Graduate School of Library and Information Science
>> University of Illinois at Urbana-Champaign
>> 501 E. Daniel Street, MC-493, Champaign, IL 61820-6211 USA
>> (217) 244-2164
>> jjett2@illinois.edu
>> 
>> 
>> 
>> On Wed, Jul 22, 2015 at 4:00 PM, Denenberg, Ray <rden@loc.gov> wrote:
>> 
>> There is a fundamental piece of this that I’m missing.
>> 
>> {
>> 
>>  "@type": "Annotation",
>> 
>>  "target": "some-uri.html",
>> 
>>  "body": {
>> 
>>    "@type": "SpecificResource",
>> 
>>    "motivation" : "editing",
>> 
>>    "source": "meme-image.jpg"
>> 
>>  }
>> 
>> 
>> 
>> You create a new resource (specific resource) in order to associate a motivation (editing) with the original resource (source).
>> 
>> 
>> 
>> And you do this to avoid  “directly assigning a role to the original resource”.
>> 
>> 
>> 
>> I understand the reason why.  What I don’t understand is how it is proposed to do the latter in the first place.  In the example, the original resource is an image. Not like it’s an RDF description that you can stick an RDF  triple into.
>> 
>> 
>> What am I missing here?
>> 
>> 
>> 
>> Ray
>> 
>> 
>> 
>> 
>> 
>> From: Robert Sanderson [mailto:azaroth42@gmail.com]
>> Sent: Wednesday, July 22, 2015 2:45 PM
>> To: Frederick Hirsch
>> Cc: W3C Public Annotation List
>> Subject: Re: [model] Clarifying annotation architecture
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>> * Associate the role with the body directly.  Fails because it makes the body un-reusable, which for the image/video or similar case is not acceptable.
>> 
>> 
>> 
>> This statement is a key issue and I think Doug was asking about this as well during the call.
>> The failure scenario is not clear. Un-resuable  : re-used by whom and for what?
>> 
>> 
>> 
>> Reused anywhere by anyone for anything, but most importantly reused as a body in a different annotation with a different role.
>> 
>> As per Doug's example, you could not use the meme image as a comment in one annotation and a replacement in another annotation.
>> 
>> 
>> 
>> 
>> 
>> If I forget the semantic web (for a moment) I can have an object, say a body, that has properties, including hasSegment or role and two bodies could have different values for the properties.
>> 
>> 
>> 
>> Sure. If I forget that I need to close my tags and put quotes around my single token attributes, I end up with SGML ... but that sure isn't XML.  Or if we conveniently forget about HTTP requirements, we could not worry about all those pesky headers. We could just stuff everything in the URL ... that would be much simpler, no? Then you would only ever need to do a GET, and could type it into your browser bar.
>> 
>> 
>> 
>> 
>> 
>> The only re-use issue would be an implementation optimization (e.g. I don't want to duplicate an embedded image/video to save space)
>> 
>> In semantic web terms:
>> annotation1 has body1.
>> annotation1 has body2.
>> body1 hasRole A.
>> body2 hasRole B.
>> 
>> 
>> 
>> annotation2 has body1
>> 
>> body1 hasRole B.
>> 
>> 
>> 
>> Now body1 has both A and B roles.
>> 
>> 
>> 
>> 
>> 
>> so where is the problem, and where is the re-use?
>> 
>> 
>> 
>> There was no problem until someone else (annotation2) also assigned a different role to the body, and now it has both of them at once.
>> 
>> 
>> 
>> 
>> 
>>> * Associate the role (motivation) with a specific resource. Works as expected without changing the semantics, breaking linked data, or introducing any new classes or properties.
>> 
>> isn't a body a resource? If it isn't a resource, what is it?
>> 
>> 
>> 
>> Well... the preferred answer would be yes, it's a resource.  But it's also a literal string :P
>> 
>> However snark aside, I'm not sure as to what's prompting the question?
>> 
>> 
>> 
>> Perhaps to clarify the bullet:  ... with a oa:SpecificResource.
>> 
>> 
>> 
>> {
>> 
>>  "@type": "Annotation",
>> 
>>  "target": "some-uri.html",
>> 
>>  "body": {
>> 
>>    "@type": "SpecificResource",
>> 
>>    "motivation" : "editing",
>> 
>>    "source": "meme-image.jpg"
>> 
>>  }
>> 
>> }
>> 
>> 
>> 
>> R
>> 
>> 
>> 
>> 
>> 
>> --
>> 
>> Rob Sanderson
>> 
>> Information Standards Advocate
>> 
>> Digital Library Systems and Services
>> 
>> Stanford, CA 94305
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> --
>> 
>> Rob Sanderson
>> 
>> Information Standards Advocate
>> 
>> Digital Library Systems and Services
>> 
>> Stanford, CA 94305
>> 
>> 
>> 
>> 
>> --
>> Rob Sanderson
>> Information Standards Advocate
>> Digital Library Systems and Services
>> Stanford, CA 94305
> 
> 
> 
> 
> 
> 


----
Ivan Herman, W3C
Digital Publishing Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
ORCID ID: http://orcid.org/0000-0003-0782-2704