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[TF-LD] minutes - 4 August 2017

From: Kazuyuki Ashimura <ashimura@w3.org>
Date: Sat, 5 Aug 2017 00:18:04 +0900
Message-ID: <CAJ8iq9Wa8=8LWQ5gGJ+c-WRQ9PQMZKjA+LDtvbRuCbxCOzxVmw@mail.gmail.com>
To: Public Web of Things IG <public-wot-ig@w3.org>
available at:
  https://www.w3.org/2017/08/04-wot-minutes.html

also as text below.

Thanks a lot for taking these minutes, Dave!

Kazuyuki

---

   [1]W3C

      [1] http://www.w3.org/

                               - DRAFT -

                             WoT IG - TF-LD

05 Aug 2017

   [2]Agenda

      [2] https://www.w3.org/WoT/IG/wiki/IG_Linked_Data_and_Semantic_Processing_WebConf#Agenda

Attendees

   Present
          Kaz_Ashimrua, Danh_Le_Phuoc, Darko_Anicic, Dave_Raggett,
          Michael_Koster, Taki_Kamiya, Victor_Charpenay,
          Achille_Zappa

   Regrets
          Maria_Poveda

   Chair
          Darko

   Scribe
          dsr

Contents

     * [3]Topics
         1. [4]Agenda bashing
         2. [5]Shape languages with the focus on Thing Description
            data types
     * [6]Summary of Action Items
     * [7]Summary of Resolutions
     __________________________________________________________

   <scribe> scribenick: dsr

Agenda bashing

   Darko runs through the agenda for today.

   [8]Agenda wiki

      [8] https://www.w3.org/WoT/IG/wiki/IG_Linked_Data_and_Semantic_Processing_WebConf#Agenda

   Dave: we could also talk the work that Maria is doing on the
   ontology and my work on JSON Schema as Linked Data.

   Darko: I also promised to look at shape languages.

   Any additional agenda items for today?

   [no]

Shape languages with the focus on Thing Description data types

   <DarkoAnicic> type system proposal (currently):
   [9]https://github.com/w3c/wot/tree/master/proposals/type-system

      [9] https://github.com/w3c/wot/tree/master/proposals/type-system

   Darko presents

   Darko shows us a side by side comparison of JSON Schema and
   schema.org

   Darko shows us his experiments (on his pc) with the SHACL and
   ShEX RDF shape rules languages

   Victor and Darko chat about the possibility of representing
   shape rules in JSON

   The examples concern validation of data, not the thing
   description

   ShEx defines its own syntax, but there is a mapping to JSON,
   albeit rather verbose

   Dave: wonders what we’re trying to achieve in this discussion?

   Darko: the idea is to use shape rules to validate the data

   Dave: I thought that we were more interested in validating
   thing descriptions?

   Darko: this is just an exploration of ideas

   Dave: I thought we had agreed to create a Linked Data model for
   a subset of JSOn Schema, right?

   Victor: we’re comparing the constraints available in JSON
   Schema with that of SHACL and SheX.

   Kaz recaps the discussion and actions from the last face to
   face relating to data types, as he is a little confused as to
   the current presentation

   Kaz: we asked Dave to look at JSON Schema and the web of things
   use cases for data types

   Darko: I am interested in the role of shape rules in relation
   to semantic validation

   It seems interesting to compare JSON Schema with shape rule
   languages in respect to applying type constraints

   (Dave notes that his own work on shape rule languages inspired
   by ATNs is being ignored)

   <kaz> Kaz: ok. if the purpose for today is rather basic survey
   of existing data type/schema languages, that's fine

   Darko shows the use of the TopBraid composer tool for use with
   SHACL

   Dave: my analysis of JSON Schema and WoT use cases:
   [10]https://github.com/w3c/wot-thing-description/issues/13

     [10] https://github.com/w3c/wot-thing-description/issues/13

   Darko: it is interesting to look at the potential for applying
   shape rules, e.g. to semantic models
   ... why is JSON schema so popular, and how does it compare to
   shape rules.

   <victor> Victor: having a schema that is object-oriented is
   important for the scripting API

   <victor> because the API itself uses the OO paradigm

   Dave: a simple toolkit of techniques for manipulating linked
   data makes it easy to apply semantic constraints etc in terms
   of operations on sets of nodes and triples

   <achille_zappa> [11]https://www.w3.org/TR/shacl-js/

     [11] https://www.w3.org/TR/shacl-js/

   DanhLePhuoc: It seems there is a lot of confusion here. RDF is
   programming language neutral. We can use the right tools for
   the task to operate on RDF in the way you want. It is quite
   different from object oriented practices

   I am also confused as to what outcome you’re seeking in this
   discussion

   Darko: we want to focus on the data types here

   DanhLePhuoc: the scripting API depends on the tasks a
   programmer is trying to accomplish

   There are lots of libraries for Java, JavaScript etc.

   Darko: the only WoT APIs available to us expose objects, and
   this makes object oriented techniques relevant

   DanhLePhuoc: if developers are using Java, they can use the
   Java libraries for linked data etc

   I don’t see why Victor want’s to limit the discussion to object
   oriented techniques

   Victor: the same linked data graph can have multiple JSON-LD
   representations

   Darko: if you define the JSON-LD context you get a single
   translation to linked data

   Dave wonders why we aren’t just considering operations on
   linked data given that this is the Linked Data and Semantic
   Processing Task Force!

   mjkoster: I think we need to remember the context for the tasks

   He talks about the payload, i.e. the formats used to represent
   linked data

   The shape rules form one RDF graph that is applied to the data
   graph

   We need to consider validation of data as a graph, and also the
   notation used to serialise it

   Darko: couldn’t we use SHACL for thing descriptions?

   mjkoster: yes, I see that as a possibility

   Dave: let’s put on the agenda for the next call the work I did
   on JSON Schema, and use cases for the web of things and the
   requirements for linked data.

   Darko: sure

   taki: we have different worlds to relate (JSON, Linked Data,
   shape rules and ontologies)

   Darko: any last points for today?

   [no]

   (Dave: see
   [12]https://github.com/w3c/wot-thing-description/issues/13 for
   my analysis)

     [12] https://github.com/w3c/wot-thing-description/issues/13

   [ adjourned ]

Summary of Action Items

Summary of Resolutions

   [End of minutes]
     __________________________________________________________


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