W3C

- DRAFT -

Thing Description task force

25 Nov 2015

Agenda

See also: IRC log

Attendees

Present
Kaz_Ashimura, Dave_Raggett, Ari_Keraenen, Dan_Romascanu, Danh_Le_Phuoc, Daniel_Peintner, Darko_Anicic, Francois_Daoust, Frank_Reusch, Kevin_Gordon, Maxim_Kolchin, Michael_Coster, Sato_Yasunori_, Takuki_Kamiya, Yingying_Chen, DanhLePhuoc, Toru_Kawaguchi, Louay_Basbouss, Jaime_Jimenez
Regrets
Chair
Darko
Scribe
dsr, kaz

Contents


<dsr> scribenick: dsr

Darko introduces the agenda.

any other agenda items beyond my email?

[no]

<kaz> Darko's agenda

Darko says that Oliver would like to join our next call on behalf of the Security TF

He wants to chat about which security topics are in scope for thing descriptions.

If there is time today we could discuss this

Discussion on limitation of open world assumption for data models

<inserted> scribenick: kaz

dsr: W3C resource description for meta data
... can be scalable
... instances can override
... this is a set of values
... very difficult to handle with RDF

kaz: Dave, do you have any concrete resource at the moment?

dsr: not now

darko: that is for semantics of the language?

dsr: how to interpret RDF triples

darko: not sure about the relationship with the TD at the moment

dsr: if we want to build process
... maybe we need to have clarity
... there is quite a lot of work

danh: what kind of semantic profiles should be applied to our work?
... RDF? OWL?
... we have resource constrained requirements
... RDF logic profile would be enough
... object oriented model might be good

dsr: large number of things have similar profiles

michael: you can't know about all possible classes
... you need to restrict classes
... appropriate reasoning for the actual world
... OWL simply specifies domain specific details

dsr: if we want to formalize TD, this is something we have to address

danh: schema.org
... mostly semantic description done using RDF
... object oriented hierarchy would be good

<DanhLePhuoc> RDFS semantics http://www.w3.org/TR/rdf-schema/

<inserted> scribenick: dsr

Darko: RDFS can be used to support closed world reasoning and may be sufficient for thing data models.

Dave: the IG needs to add a task to work on use cases and examples and the requires that emerge.

Danh: we should consider the logic profile and the level of computational load involved so that we can see what’s practical for resource constrained devices.

Dave: I think we should aim to cover this in the IG report we’re expecting to produce early next year.

Darko: I will take a note to ensure that we can track this.

Dave thanks Darko for placing this on the agenda today.

<DanhLePhuoc> I can help Dave with that

Michael: I very much agree with Dave on the need to collect the use cases and requirements, there could be some interesting examples, e.g. discovery and filtering. People should be able to add use cases as they come across them.

Darko: discovery is one of the use cases effected by the open/closed world assumption.

Another deals with default values for properties and method arguments.

Michael: discovery is one area, another is overrides for an instance over the definition for a class or devices (of device prototypes).

Kaz: we may want to have joint calls with the discovery task force in relation to this issue.

Darko: any further comments on this topic?

<kaz> darko: how we could manage issues?

<kaz> dsr: we can use GitHub issue tracker

wot IG issue tracker or W3C issue tracker http://www.w3.org/WoT/IG/track/

Dave: suggest using the W3C issue tracker for IG and TF issues, and GitHub tracker for specific documets e.g. IG reports.

Michael: Github’s tracker is per repositiory

<scribe> ACTION: Kaz to ensure that GitHub forwards issue tracking messages to the WoT IG public list [recorded in http://www.w3.org/2015/11/25-wot-td-minutes.html#action01]

<trackbot> Created ACTION-15 - Ensure that github forwards issue tracking messages to the wot ig public list [on Kazuyuki Ashimura - due 2015-12-02].

Technical Landscape survey

<kaz> TD landscape wiki

Darko talks us through the structure of the wiki. There are tables and additional wiki pages to provide more details. He invites volunteers to help with this.

We also intend to switch over to GitHub for the IG report we will make from this.

Michael: I currently can’t update the wiki and would very much prefer to work on a GitHub doc

<inserted> scribenick: kaz

darko: what was the consensus at the f2f?

dsr: moving to GitHub was the consensus

<dsr> ACTION: Darko to work with Sebastian on setting up a document for the landscape survey on github [recorded in http://www.w3.org/2015/11/25-wot-td-minutes.html#action02]

<trackbot> Created ACTION-16 - Work with sebastian on setting up a document for the landscape survey on github [on Anicic Darko - due 2015-12-02].

<scribe> scribenick: dsr

Danh: I made a start on the wiki, but I too would prefer GitHub and to use pull requests

I agree with tracking contributors and splitting the work up as appropriate

Darko: should we just use the wiki page structure or try something else?

Danh: I wasn’t at the F2F and am unsure about some of the columns.

We need examples, so the table isn’t particularly attractive

Dave: I would advise a free text description with examples for each area, and to then work on using tables for summaries that show the relationships between the different approaches.

Danh: I agree with that

<kaz> +1

Darko: okay I will prepare a document outline accordingly

any other points to raise now?

Dave: we will need to be flexible about adding new approaches, e.g. on manufacturing (having just come back from Manufuture conference on smart manufacturing)

WoT WG items related to TD-TF

<inserted> WG items proposal

Darko: what about missing work items?

Jaime: is HATEOAS part of the work items?

Darko: read the work items for their definition.

I don’t think that the current 2 work items mention HATEOAS.

Michael: there was a lot of discussion aroud HATEOAS, but should we treat it as a technology or an application feature.

Would we work with schema.org ...

I don’t thiink of HATEOAS as a separate work item, but more as something relevant across several

<kaz> dsr: scribenick: kaz we need to clarify the relationship between the Web architecture and HATEOAS

<inserted> scribenick: dsr

Dave: I would like to see some discussion about the relationship between the core web architecture (addresses, declarative resources, protocols) and HATEOAS.

Darko: we need links from one thing description to another.

Michael: I don’t see how thing descriptions will drive all the state transitions

I agree with Dave that thing descriptions are analogous to HTML and includes links

but I think it should also include everything needed for state transitions.

How are state transitions driven and this is a question of web architecture

Darko: Joerg would like to see hypermedia as a thread across work items, and so how does this fit?

Jaime: if nobody takes ownership we should perhaps keep this for later

Danh: behaviour may be through scripting languages or state transition machines, I don’ t think we need a new work item here.

Darko: we don’t want to leave this to be forgotten.

Danh: discovery is one use case and the discovery task force should be interested.

Michael: some but not all protocols would be driven by hypermedia

<Zakim> kaz, you wanted to mention SCXML for explicit state transition control

Kaz: W3C has a standard for state transition models - SCXML, which could be of interest

Dave: there are a family of state transition languages we should survey

Jaime: perhaps this is something we can cover in joint meetings with the IETF

<michael> discovery driven by hypermedia, some protocols , http and coap, more than others, also scripting is driven to the extent of the underlying protocols

Ari: in the T2TRG we will continue to work on HATEOAS

At the last joint W3C/T2TRG meeting the consensus was that we need more experience, and joint plugfests will help with that

<michael> also TD somehow maps to hypermedia controls, maybe as part of the same data model or a separate data model linked to

Darko: we could continue discussions here

Ari: I want us to be aware of the work in the T2TRG on HATEOAS and discuss it as needed

<akeranen> yes, agree

Darko asks Michael to look at which task forces could be discussing HATEOAS

Michael: I will have a look at this and make some suggestions

Dave: we can cover external liaisons in the WG charter
... We need more supporters for the work on a vocabulary for server metadata as this is critical

Darko: if you have suggestions for other work items please let us know

Security metadata

Darko: we have yet to discuss access control to metadata, and we should spend time on coming up with use cases etc.

Dave: I agree with that, but also think we will need to work on use cases for security metadata more generally

Darko: we need volunteers

Dave: I agree with making time for this in future TD-TF calls

Darko: okay I will check back with Oliver

Kaz: the W3C Auto WG has a long list of use cases and we may want to include them in our discussions

Darko: okay

any other business for today [no]

scribe: end of meeting …

Summary of Action Items

[NEW] ACTION: Darko to work with Sebastian on setting up a document for the landscape survey on github [recorded in http://www.w3.org/2015/11/25-wot-td-minutes.html#action02]
[NEW] ACTION: Kaz to ensure that GitHub forwards issue tracking messages to the WoT IG public list [recorded in http://www.w3.org/2015/11/25-wot-td-minutes.html#action01]
 

Summary of Resolutions

[End of minutes]

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$Date: 2015/11/25 14:30:21 $

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ScribeNicks: dsr, kaz
Present: Kaz_Ashimura Dave_Raggett Ari_Keraenen Dan_Romascanu Danh_Le_Phuoc Daniel_Peintner Darko_Anicic Francois_Daoust Frank_Reusch Kevin_Gordon Maxim_Kolchin Michael_Coster Sato_Yasunori_ Takuki_Kamiya Yingying_Chen DanhLePhuoc Toru_Kawaguchi Louay_Basbouss Jaime_Jimenez
Agenda: https://lists.w3.org/Archives/Public/public-wot-ig/2015Nov/0041.html
Got date from IRC log name: 25 Nov 2015
Guessing minutes URL: http://www.w3.org/2015/11/25-wot-td-minutes.html
People with action items: darko kaz

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