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RE: SDW meeting this week: approve FPWD for SSN

From: <Simon.Cox@csiro.au>
Date: Wed, 25 May 2016 00:21:38 +0000
To: <frans.knibbe@geodan.nl>, <rob@metalinkage.com.au>
CC: <janowicz@ucsb.edu>, <public-sdw-wg@w3.org>
Message-ID: <60678c3a5ee749deac95f0ae3cd141d2@exch1-mel.nexus.csiro.au>
Ø  if the STA was based on SSN for example

Steve Liang was involved in the OGC SWE activity almost from the beginning, so the Calgary team was very aware of the OGC standards, such as O&M.
SSN is a later arrival into the OGC process.


Ø  Also, it could be that SSN will not get the attention it deserves

SSN gets huge attention in the academic literature – very highly cited.

However, I think we are seeing some of the effects of the different ecosystems which the academic and standards literature inhabit. They are almost mutually invisible to each other – very little formal citation of standards in the research literature, and university libraries generally do not have subscription arrangements with ISO. Meanwhile, the development of ‘standards’ in some of the forums seem to chug on semi-independently of developments in the research literature. W3C and this joint working group are an opportunity to bridge the divide, but does need both sides to appreciate the working methods and constraints from the other. In particular, the consensus process sometimes results in a camel instead of a racehorse.

From: Frans Knibbe [mailto:frans.knibbe@geodan.nl]
Sent: Tuesday, 24 May 2016 7:02 PM
To: Rob Atkinson <rob@metalinkage.com.au>
Cc: Krzysztof Janowicz <janowicz@ucsb.edu>; SDW WG Public List <public-sdw-wg@w3.org>
Subject: Re: SDW meeting this week: approve FPWD for SSN



2016-05-24 0:47 GMT+02:00 Rob Atkinson <rob@metalinkage.com.au<mailto:rob@metalinkage.com.au>>:

Possibly very naive take on this, but I feel Frans' pain here :-)

Apart from a bad knee, which is another matter, I don't feel much pain. But I suspect things may be hard for the people looking for an OGC-approved standard to work with sensor data. Which to choose? STA and SSN seem to be mutually exclusive, although one could use SSN to fill in the things that are not specified yet in STA. Also, it could be that SSN will not get the attention it deserves on account of it being too intellectual or complex-looking, despite the modularization and other efforts to lower the threshold for potential users. Requirements for reasoning and inferencing might not be already apparant when a choice for a standard is made.

From a user's perspective it would be great if a choice between the two standards does not have to be made, if the STA was based on SSN for example. I understand STA can not be changed now, but could a future version of the STA data model be an SSN application profile?

Regards,
Frans


Let us consider the "vertical" modularity proposal - as I think it potentially helps us untangle and provide a means to help the poor user being introduced to this ecosystem:

Lets each module is itself annotated according to a vocabulary that defines its role, something like xx:ontologyType may be (xx:owl-dl, xx:registration, xx:schema, xx:serviceProtocols, xx:alignment, xx:annotation, xx:proxy=a vocabulary based on another style of spec. )

Then we can describe the scope of each specification in terms of what it does relative to SSN - and SSN can both help resolve the problem, and I suspect gain some useful tools to separate concerns.

obviously xx: is not a SSN domain - but we could put it in OGC as its about distinguishing schemas and services - or push it up to W3C. As its only annotation, we dont need to make anything depend on it - annotation using xx: could be a valid type of vertical module. And we only need two note about intention to address scope overlap in the FPWD - one in a scope statement at the top and another in the modularisation intent section.

Has anyone got an existing best practice or counter-proposal that allows us to clearly distinguish between the concerns of schema definition, inferencing, etc (the xx:* vocab? )

Rob


On Tue, 24 May 2016 at 02:42 Krzysztof Janowicz <janowicz@ucsb.edu<mailto:janowicz@ucsb.edu>> wrote:
Hi,



SSN specifies similar concepts, plus or minus various constraints on those concepts and their relationships. One “could” use HTTP methods to interact with resources based on SSN concepts. How to do that has not yet been specified in any detail except to the extent that all HTTP REST API’s are similar since they are based on HTTP.

I know what you mean, but just for the sake of being overly picky, the Linked Data paradigm defines the interaction in case of the SSN.



As I mentioned earlier, there is potential for STA extensions to provide a service interface for SSN in the future, and it is certainly worthwhile to keep that in mind. It’s may also be true that resource models and ontologies can look very similar and one may be derived from the other, but I don’t think they are the same thing.


Agreed.  Resource models and ontologies share some common features but they differ greatly. For instance, the formal semantics of ontology languages such as OWL is geared towards making inferences and not towards modeling constraints.

Best,
Krzysztof



On 05/23/2016 09:15 AM, Joshua Lieberman wrote:
Frans,

“Looks like” can be misleading ;>). STA specifies how to interact with certain resources using HTTP methods and patterns from OData.  The particular resources specified for STA are based on SWE / O&M concepts, although it is unknown whether any axioms that might be implied by the STA resource model conflict with any defined by omlite.

SSN specifies similar concepts, plus or minus various constraints on those concepts and their relationships. One “could” use HTTP methods to interact with resources based on SSN concepts. How to do that has not yet been specified in any detail except to the extent that all HTTP REST API’s are similar since they are based on HTTP.

As I mentioned earlier, there is potential for STA extensions to provide a service interface for SSN in the future, and it is certainly worthwhile to keep that in mind. It’s may also be true that resource models and ontologies can look very similar and one may be derived from the other, but I don’t think they are the same thing.

Josh

On May 23, 2016, at 11:54 AM, Frans Knibbe <frans.knibbe@geodan.nl<mailto:frans.knibbe@geodan.nl>> wrote:

Hello Josh,

Thank you for the information. I do wonder if the distinction between an ontology (SSN) and an interface specification (STA) is all that clear. The diagram of the datamodel of the SensorThings API<http://ogc-iot.github.io/ogc-iot-api/datamodel.html> looks a lot like an ontology and defines similar things as SSN does. And since SSN is a web ontology, the API that people will use with the st.andards can also be similar (HTTP GET, POST, PATCH, DELETE).

Regards,
Frans


2016-05-23 16:10 GMT+02:00 Joshua Lieberman <jlieberman@tumblingwalls.com<mailto:jlieberman@tumblingwalls.com>>:
Frans,

Some observations and clarifications:


  *   Sensor Things API (STA) is presently an adopted OGC standard.
  *   It is a compatible REST-based profile of existing SWE interface standards, particularly it is also based on the O&M information model.
  *   As a profile, it is compatible with and complementary to existing standards, such as SOS and SPS, not a replacement.
  *   SSN is an ontology, not a service interface specification, so there should not be a direct conflict between SSN and STA, just as there isn’t necessarily conflict between RDF / OWL and Linked Data API or SPARQL API.
  *   To the extent that SSN is / becomes an elaboration of O&M, there is room to make extensions of STA that incorporate the additional concepts and relationships of SSN, such as more elaborate sensor descriptions.
  *   The more direct overlap is probably that between SSN and SensorML and this may require some harmonization work for OGC standards consistency.
Josh

On May 23, 2016, at 9:58 AM, Frans Knibbe <frans.knibbe@geodan.nl<mailto:frans.knibbe@geodan.nl>> wrote:

Hello Kerry,

A colleague just showed me his work on publishing and consuming sensor data. He uses the OGC SensorThings API<http://www.opengeospatial.org/projects/groups/sensorthings> and is happy with its capabilities and simplicity. I am not sure how far SensorThings API is in the process of becoming an official OGC standard, but it is clear that there is lots of overlap with SSN. In the introduction of the SSN FPWD it says it can be regarded as a modern replacement for OGC's Sensor Web Enablement standards. But the same thing can be said about the SensorThings API. So questions that come to mind are:

  *   Why is the OGC working on development of two standards for the same thing?
  *   If both SSN and the SensorThings API are to become OGC standards, to what extent are they interoperable?
  *   Is there some kind of collaboration between standards developers?
Is it possible to devote some words about other standards that are presently in development in the introduction? Perhaps the  W3C Generic Sensor API<https://w3c.github.io/sensors/> can also be mentioned?

Regards,
Frans

2016-05-23 8:48 GMT+02:00 Kerry Taylor <kerry.taylor@anu.edu.au<mailto:kerry.taylor@anu.edu.au>>:
Hi all,
As planned, the editors of SSN would like to transition  the current SSN editors’ draft (http://w3c.github.io/sdw/ssn/ dated 23 May) to the status of “First public working draft” in the w3c and “discussion paper” in OGC.
Please do have a good look before the telecon this week, and do please remember that there is nothing final about this – it is much more a statement of intent and options  littered with “issues” than a specification.

--Kerry






--

Krzysztof Janowicz



Geography Department, University of California, Santa Barbara

4830 Ellison Hall, Santa Barbara, CA 93106-4060



Email: jano@geog.ucsb.edu<mailto:jano@geog.ucsb.edu>

Webpage: http://geog.ucsb.edu/~jano/


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Received on Wednesday, 25 May 2016 00:22:30 UTC

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