Re: A look at WoT specs from Linked Data and AWWW perspective

Dave,

then I see this as a failure of the specification. If the WoT specs merely
specify the exchange of JSON messages and it schemas, what does it achieve?
We already have HTTP for that. How does it advance the interoperability of
IoT devices?

I think rather than being message-agnostic, WoT should work on a domain
vocabulary and should integrate closer with SSN:
https://www.w3.org/TR/vocab-ssn/
I see SSN only mentioned once (!) in the text. How so?

My main point: if WoT is to become a cornerstone specification for millions
of devices on the web, the interoperability has to be absolutely
bullet-proof. I mean space-mission bullet-proof. And that takes a sound,
formally verifiable abstract model(s), in the form of algebras, semantics,
and so on.
Currently I see nothing of that sort, only prose "definitions" and a bunch
of JSON examples -- that will not cut it.

These articles, even if long, explain my point rather well:
https://www.theatlantic.com/technology/archive/2017/09/saving-the-world-from-code/540393/
https://www.quantamagazine.org/formal-verification-creates-hacker-proof-code-20160920


On Fri, Apr 6, 2018 at 11:03 AM, Dave Raggett <dsr@w3.org> wrote:

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> On 6 Apr 2018, at 09:24, Charpenay, Victor <victor.charpenay@siemens.com>
> wrote:
>
> > JSON is only one of the syntaxes -- RDF is the model, and constraints
> should be based on it.
>
> Not exactly. RDF is the foundation of the TD model, sure. But the schemas
> embedded in a TD model the data a device exposes, not the TD. That data
> model can be based on SenML or the BLE GATT specification, for instance.
> WoT devices typically exchange once a TD and ten, hundred times sensor
> data. It is important to optimize the latter exchanges; RDF would introduce
> a significant overhead and is therefore not a good candidate. If it is
> necessary to merge data and meta-data (e.g. a TD or some SSN description of
> a system), one would have to perform RDF lifting, which is a pretty
> well-known procedure (see for instance, RML or SPARQL Generate).
>
>
> I am not quite sure what Martynas is signifying in his comment.  I agree
> with the idea that constraints should be expressible in terms of the RDF
> model for how applications expose and interact with things as objects.
> However, there is developer interest in simple use of JSON to express data
> types. This can be mapped to constraints on the corresponding RDF model and
> as you suggest to RDF shape rules in SHACL, however, applications can more
> simply directly use the JSON expression to apply the constraints to the
> data.
>
> Dave Raggett <dsr@w3.org> http://www.w3.org/People/Raggett
> W3C Data Activity Lead & W3C champion for the Web of things
>
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