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JSON-LD Telecon Minutes for 2012-11-06

From: Manu Sporny <msporny@digitalbazaar.com>
Date: Tue, 06 Nov 2012 14:52:30 -0500
Message-ID: <50996A7E.20701@digitalbazaar.com>
To: Linked JSON <public-linked-json@w3.org>
CC: RDF WG <public-rdf-wg@w3.org>
Thanks to Gregg for scribing! The minutes from this week's call are now
available here:


Full text of the discussion follows including a link to the audio

JSON-LD Community Group Telecon Minutes for 2012-11-06

   1. Brief review of RDF WG Face-to-Face
   2. JSON-LD Breakout Session
   3. Strategy for addressing pre-LC RDF WG issues
   4. Review of new issues
   5. ISSUE-159: Add specifying @language to expanded form
   1. A feature freeze is in effect for JSON-LD 1.0 Syntax and
      JSON-LD 1.0 API effective November 06th 2012.
Action Items:
   1. Manu to send a note to the LDP and WebID groups noting
      their selection of Turtle, and suggest they consider JSON-LD.
   2. Gregg to create an issue to track the differences between
      graphs and datasets in JSON-LD.
   3. Gregg to write up proposal in language maps.
   Manu Sporny
   Gregg Kellogg
   François Daoust, Gregg Kellogg, Markus Lanthaler, Manu Sporny,
   Richard Cyganiak, Niklas Lindström, David I. Lehn

François Daoust:  As part of the brief on the RDF WG F2F - I ran
   a session on JSON-LD, it would be good to review that. [scribe
   assist by Manu Sporny]
Gregg Kellogg is scribing.

Topic: Brief review of RDF WG Face-to-Face

Markus Lanthaler: François, did you perhaps create a diff for the
   changes you made? quite difficult to read it on github..
Manu Sporny:  I'd like to briefly review discussions from the
   F2F. Try to keep comments fast.
Manu Sporny:

   … We had a fairly good discussion about JSON-LD last week.
   There have been several offline discussions prompted from this.
François Daoust: Markus, I haven't but will do.
   … I've added all issues that were raised in the RDF WG into
   the issue tracker.
Markus Lanthaler: thanks, just upload it somewhere.. no need to
   put it into the repo
   … The biggest concern comes down to the differences in the
   data models and potential miss-alignment between them.
   … The biggest concern that that there _was_ a difference. Once
   we discussed that it is a consequence of the spec approach, there
   is still a desire to align them.
Gregg Kellogg:  I think basically, the question of "Is JSON-LD,
   RDF?" is the general push. [scribe assist by Manu Sporny]
Gregg Kellogg:  I think we have expressed a desire that
   everything in JSON-LD can be converted to RDF. [scribe assist by
   Manu Sporny]
Richard Cyganiak:  There's a question of if JSON-LD is a graph
   syntax, a dataset syntax or both.
François Daoust: Markus, here is a diff: http://goo.gl/bUZPM
   (loses most styles, but text remains readable), will add the
   reference to the issue tracker
   … In the RDF WG there's been a consensus that graph and
   dataset syntaxes should be disjoint.
Markus Lanthaler: tidoust, thanks a lot!
   … If you think of JSON-LD as a graph syntax that can also
   serialize datasets, it goes against this assumption, but it
   hasn't been discussed yet.
Gregg Kellogg:  This comes about from TRiG - are curly braces
   required for a 'default graph'? [scribe assist by Manu Sporny]
Gregg Kellogg:  If you treat a document as if it is a graph, you
   could import the data from the default graph into a particular
   location. This was one of the reasons why it's not entirely
   resolved. Curly braces might still be required for the 'default
   set' in TRiG. In JSON-LD, there is no way to specify when you
   have something different than JSON-LD... maybe we need a new
   MIMEType for JSON-LD. [scribe assist by Manu Sporny]
Markus Lanthaler:  it's just about what parsers are going to
   expect, and in JSON-LD it's clear that it may include named
   graphs in additional to the default graph.
   … I don't see it as a problem in JSON-LD.
Markus Lanthaler:  also an issue if we should have a WebIDL API,
   or just processing rules.
Richard Cyganiak:  There is a statement in the RDF WG that
   JSON-LD makes the same mistakes as RDF/XML.
   … Manu pointed out that this statement isn't useful, to be
   constructive it would need to be backed up with details on how it
   can be addressed.
   … I wanted to acknowledge that it is not a useful statement
   and needs to be backed up, but there probably is something that
   needs to be considered.
Manu Sporny:  The problem with that statement is that we can't
   really respond to it as there are many mistakes made by RDF/XML,
   what is it that we need to address.
Markus Lanthaler:  In an offline discussion with Sandra, he
   mentioned that JSON-LD is trying to be the master of multiple
   domains, and when you do this, you come up with something
Gregg Kellogg:  Once criticism I hear of RDF/XML is that there is
   many different ways to say the same thing - indeed that's true in
   JSON-LD... as it is in TURTLE. [scribe assist by Manu Sporny]
   … We need to understand specific weaknesses, not broad
Niklas Lindström:  If you look at JSON-LD and through it into a
   templating system, you have a similar problem that you don't know
   the shape of the data. THe key difference is that JSON-LD has a
   context that allows you to remove these.
   … The key pieces missing are framing and graphiphy that are
   the key to being to finally address shape differences.
   … With connect, I've been able to do much more templating than
Markus Lanthaler: +1 to all what niklas just said
Gregg Kellogg:  The 'flatten' option does allow you to get a
   consistent shape. [scribe assist by Manu Sporny]
Niklas Lindström:  after flatten, you can do connect in a few
   lines of code.
Manu Sporny:  these are things that people in the RDF WG may not
   be aware of, because they didn't know about them, or are not
   programmers and can't appreciate the benefits.

Topic: JSON-LD Breakout Session

François Daoust:  I had a breakout session at the "BAR Camp"
   event at TPAC.
   … It's fair to say that most people were RDF/Linked Data guys.
François Daoust: http://www.w3.org/2012/10/31-ld-dev-minutes.html
   … I don't think there's much take away, it was more informal.
   … It was really interesting to have the Linked Data Platform
   WG folks.
Manu Sporny:  Were the LDP WG folks interested, is it useful?
François Daoust:  JSON-LD isn't their priority for the time
   being. Different people have different views.
   … I only attended the first day of the LDP WG F2F.
   … There was a question of relating JSON Schema with JSON-LD
   … There is overlap in the syntax, and this was probably the
   most interesting question.
Manu Sporny:  in the Web Payments group, we use JSON Schema to
   validate input into the system, buy using our context and frame
   the data such that the structure is regular and then we apply
   JSON schema against that. It works extremely well.
François Daoust:  the main point from "RDF guys" is that they
   want to work with the data model (triples) and don't necessarily
   like the way it approaches it.
Manu Sporny:  you don't need JSON-LD if you have a triple store.
Richard Cyganiak:  I was surprised at how large the turnout was,
   it was by far the largest I attended.
   … It seems to hit the right memes that bring people in from
   different places.
   … At LDP WG, the question of format is relevant.
   … They used to say you need to use Turtle to be compliant, but
   they removed RDF/XML. You may support other formats.
   … JSON-LD wasn't specifically mentioned, but it probably
   should have been.
Manu Sporny:  We should discuss this with the LDP WG, but it
   could be a multi-month discussion and reduce our ability to
   complete work.
Richard Cyganiak:  it might be helpful to bring it up sooner
   rather than later. It's a fresh issue; it's been resolved, but
   immediate push-back might make a difference.
François Daoust: [Link to the "closed for the time being" issue
   in the LDP WG: http://www.w3.org/2012/ldp/track/issues/22 ]
   … According to LDP charter is due in May 2013. I wouldn't be
   totally surprised if it's delayed.
Gregg Kellogg:  I've noticed similar things come up on some
   outcomes from TPAC from WebID - normative use of TURTLE... many
   members of the group seem to object to that. [scribe assist by
   Manu Sporny]
Gregg Kellogg:  I think that LDP is using TURTLE normatively
   might align with the WebID work, although I think it's clear to
   the folks in this group that any Web-based format could benefit
   highly from JSON-LD. [scribe assist by Manu Sporny]
Manu Sporny:  I don't expect the WebID folks to turn away from
   … However, it doesn't mean we shouldn't try.

ACTION: Manu to send a note to the LDP and WebID groups noting their
selection of Turtle, and suggest they consider JSON-LD.

Richard Cyganiak: resolution to use turtle in LDP is here:
Niklas Lindström:  mention that with JSON-LD you can use RDF
   structures only using JSON.

Topic: Strategy for addressing pre-LC RDF WG issues

Manu Sporny:  we've had a garage of issues over the last 2 weeks.
   … We signed up to have LC docs by the end of January, which
   means we need to resolve issues faster.
   … I propose that we deal with the issues purely in the issue
   tracker, with +/-1 in the issue and commit from there.
   … Reserve telecon time for contentious issues.
   … we have a long cycle where it takes a while to commit text
   from resolutions.
Markus Lanthaler:  perhaps we should note that we're freezing
Manu Sporny:  A freeze is good, but we should note that we can do
   small things.

PROPOSAL:  A feature freeze is in effect for JSON-LD 1.0 Syntax
   and JSON-LD 1.0 API effective November 06th 2012.

Manu Sporny: +1
Gregg Kellogg: +1
Markus Lanthaler: +1
Niklas Lindström: +0.9
Richard Cyganiak: +1 (in case I get to vote :-)
François Daoust: +1
David I. Lehn: +0

RESOLUTION: A feature freeze is in effect for JSON-LD 1.0 Syntax
   and JSON-LD 1.0 API effective November 06th 2012.

Manu Sporny:  is anyone opposed to using the issue tracker to
   close issues.
Richard Cyganiak:  I think that some issues may be best dealt
   with by pushing back rather than implementing.
   … There's a slight risk that if you do edits directly, they
   might not be necessary.
Manu Sporny:  agreed. What would have to happen is that we would
   need consensus within the issues.
   … We could only make an edit if there is a consensus view (no
Richard Cyganiak:  I think it would be a good idea to do a quick
   call for consensus, or in the issue, giving a 24 hour period
   before it will take effect.
Manu Sporny:  editors will check for consensus and resolve when
   there is.
Manu Sporny:  when the editors note the resolution, they will
   send an email to the JSON-LD mailing list saying that the
   resolution has been made and will take effect within 24 hours.
Richard Cyganiak: how about: send an email: "call for consensus
   on issues x, y, and z. if you have additional concerns not yet
   raised there, please do so before xxx"
Richard Cyganiak:  the assumption is that if no one raises a
   concern that discussion has completed.
François Daoust:  do we need to raise issues for small editorial
   changes? no.

Topic: Review of new issues

Manu Sporny: Clarify sets and lists -
Manu Sporny:  there was a concern that it wasn't clear if there
   was difference between sets and lists.
   … Ivan things having @set is confusing, Turtle doesn't have
   anything like that.
Niklas Lindström:  I agree, that @set is gratuitous.
Richard Cyganiak: +1 to either
François Daoust: [I don't understand why "@set" creates a problem
   and like symmetry but am ok with removal as well]
Manu Sporny: JSON-LD data model clarifications -
Manu Sporny:  a long thread with cygri on the data model. It has
   been productive.
Richard Cyganiak:  I plan to finish the mapping this week.
Gregg Kellogg:  I think that there is the Graph/Dataset thing
   we're not very clear on - I think we describe JSON-LD as creating
   a graph, but it glosses over the Dataset aspect of it. There is
   something to be set about calling it a "Dataset model" [scribe
   assist by Manu Sporny]
Gregg Kellogg:  We should mention the Dataset aspect of it.
   [scribe assist by Manu Sporny]
Markus Lanthaler:  Isn't that what a JSON-LD document is? [scribe
   assist by Manu Sporny]
Gregg Kellogg:  Dataset is abstract, JSON-LD document is concrete
   syntax. [scribe assist by Manu Sporny]
Manu Sporny:  We need an issue to discuss this.

ACTION: Gregg to create an issue to track the differences between graphs
and datasets in JSON-LD.

Niklas Lindström:  We need to be sure we don't end up with
   something that only represents datasets.
   … It's important that a JSON-LD document be useable as a named
   graph, even if it describes a default graph.
Manu Sporny: Rephrase "adding meaning" in Syntax specification -
Manu Sporny:  sandro things that "adding meaning" doesn't
   actually add meaning.
Niklas Lindström: .. sandro suggested: "it means adding
   information which enables disambiguating the relational structure
   and the identities of the elements of that structure"
Richard Cyganiak:  there might be some useful phrases that could
   come in if we push back.
Manu Sporny: Make link to RDF more apparent in the specification
   - https://github.com/json-ld/json-ld.org/issues/180
Niklas Lindström:  something which captures the essence of this
   phrase in "normal speak".
Manu Sporny:  david wood wants to see something more specific in
   the spec that JSON-LD is an RDF specification.
Richard Cyganiak: +1 to a sentence in the introduction
   … I'm fine with putting something in the intro.
Gregg Kellogg: +1
Niklas Lindström: +1
François Daoust: +1 to adding a sentence.
Manu Sporny: Consider renaming JSON-LD API to JSON-LD Core
   Processing - https://github.com/json-ld/json-ld.org/issues/178
Manu Sporny:  Ivan brought this up. The concerns are that the RDF
   WG doesn't have the constituency to create WebID.
   … The other concern is that having WebIDL being normative is
Richard Cyganiak: "JSON-LD Processing and Data Model"? And keep
   the API part in?
Manu Sporny:  we could either split the WebIDL out or keep it in
   as an appendix.
Gregg Kellogg:  Richard had a great e-mail earlier today
   regarding orthogonality in specs - particularly relating to
   strongly relating Syntax with Behavior. That orthogonality
   argument also relates to having a concrete WebIDL API as a part
   of the specification. [scribe assist by Manu Sporny]
Gregg Kellogg:  Doing so tends to limit the appliciability of the
   specifications, it's crossing over in domains - it's not key in
   what they're trying to accomplish. [scribe assist by Manu Sporny]
Richard Cyganiak:  I didn't have JSON-LD in mind when sending
   this email; it really is about RDF Concepts. Anything you do
   there has consequences depending on how other specs depend on it.
   … If you have something new, that doesn't have such
   complicated interdependencies, it is not necessarily a bad thing,
   and there is a cost in separating things into multiple documents.
François Daoust:  I would prefer that we leave the WebIDL in; if
   we move it, it could just disappear.
   … The syntax and the algorithm are tightly tied together, and
   right now, it's an informative reference.
   … I would have only a single document.
   … It shouldn't be a problem to have each normatively reference
   the other.
Markus Lanthaler:  we should keep in mind the different audiences
   for each document.
   … The RDF WG is more interested in the algorithms.
   … We should be clear on the audience.
   … I don't think we need a normative reference from the Syntax
   to the API, but it is just a minor edit.
Manu Sporny:  one reason is that there are two specs is that we
   decided early on that we shouldn't tightly link them as it might
   make a problem going to REC.
   … We also tried to make sure there are no normative references
   from Syntax to API.
   … I think the positive effect of splitting the two is that it
   makes the Syntax spec stand alone, and could allow us to go to
   rec at a different pace.
Richard Cyganiak:  I think specs should be written with
   implementers in mind foremost.
   … In this case, it makes sense to focus on implementers of the
   algorithms; developers just need the API documentation.
   … It might be better communicated using documentation of a
   particular library.
   … If you believe that the documentation can be provided
   differently, it makes less sense to keep them separate.
Markus Lanthaler:  it's more about the message if you call it
   "Core Processing" rather than "API".
   … I would say that developers are more likely to look at an
   API spec, rather than one which is focused around algorithms.
Manu Sporny: Consider moving WebIDL to Appendix or Note -
François Daoust:  moving to an appendix doesn't really change
   anything in practice.
Manu Sporny:  we wanted to give the reader a gentle intro to the
   material. The WebIDLE seemed to be the easy way into the
Gregg Kellogg:  If we do rename it as Core Processing, it makes
   sense to move the WebIDL down to an appendix. This is an issue
   that was of big concern in the RDF WG. [scribe assist by Manu
   … Ivan's reading it differently, in that if you don't
   correspond exactly to the WebIDL.
Niklas Lindström:  I agree with the change to "Core Processing".
   … It feels better.
Manu Sporny:  two big issues: JSON-LD to RDF data model mapping.

Topic: ISSUE-159: Add specifying @language to expanded form

   … The other is the language container discussion.
   … We're still trying to figure out what we're going to do,
   BNodes or @language syntax, and just do in RDF.
Gregg Kellogg:  I think I'm in the minority when I want to create
   bnodes for language maps in expanded form. [scribe assist by Manu
Gregg Kellogg:  I did discuss this at length w/ Lin - she is
   concerned about this not being in the best interest of Drupal.
   [scribe assist by Manu Sporny]
Markus Lanthaler: Richard, would be very interested hearing your
   opinion on this, e.g., introduction of jsonld vocab vs.
Gregg Kellogg:  I think differently, I think we're creating a
   divergence in the JSON-LD data model and the RDF data model - I'm
   not as sympathetic to the concerns in expanded form that there
   are some nodes represented there. [scribe assist by Manu Sporny]
Gregg Kellogg:  However, unless there is support for bnodes in
   expansion, I think we'll have to go the other way. [scribe assist
   by Manu Sporny]
Niklas Lindström:
Niklas Lindström:  I also feel that BNodes in expanded form are a
   better way to go.
   … Perhaps we don't need an intermediate BNode if we fold
   @language into the resource, and relate it to dc:language, say.
Richard Cyganiak: Markus, I haven't fully followed the discussion
   so far I'm afraid
Gregg Kellogg:  I need to look at it in more depth. [scribe
   assist by Manu Sporny]
Markus Lanthaler: Richard, basic question is how to
   "language-tag" resources
Niklas Lindström:  I am concerned about moving too far away from
Manu Sporny:  I'm not so concerned about divergence between
   JSON-LD and RDF data models, but more concerned with the Drupal
   … If we do the translation to a BNode we're working against
   what the spec enables.
   … It seems like it will be more difficult for developers to
   work with expanded form.
Markus Lanthaler:  Are we going to allow nodes to be language
   tagged or not. If we are, then we need to either introduce
   vocabulary or @language.
   … This allows us to split JSON-LD from RDF mapping.
Niklas Lindström:  I think the intermediate BNode might not be
   necessary, if we interpret @language to map to dc:language.
Manu Sporny:  If we take Markus' points and separate @language
   being in expanded form, and taking the mapping to dc:language as
   being difference.
Gregg Kellogg:  I think this approach is good - clear mapping to
   RDF (we use dc:language) [scribe assist by Manu Sporny]
Gregg Kellogg:  we also avoid bnodes in expanded form... we may
   want to mint a JSON-LD namespace property that has a link with
   dc:language? [scribe assist by Manu Sporny]
Gregg Kellogg:  Is there a similar property in RDF to
   dc:language? [scribe assist by Manu Sporny]
Gregg Kellogg:  I think binding to dc:language to it doesn't make
   it weaker. [scribe assist by Manu Sporny]
Manu Sporny:  let's just bind @language to dc:language in the

ACTION: Gregg to write up proposal in language maps.

-- manu

Manu Sporny (skype: msporny, twitter: manusporny)
President/CEO - Digital Bazaar, Inc.
blog: HTML5 and RDFa 1.1
Received on Tuesday, 6 November 2012 19:53:06 UTC

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