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Re: Point of objection RE: State of SSN: arguments in favour of a single name and namespace, proposal, the SEAS example, proposal of action

From: Phil Archer <phila@w3.org>
Date: Fri, 3 Feb 2017 10:51:07 +0000
To: Kerry Taylor <kerry.taylor@anu.edu.au>, "janowicz@ucsb.edu" <janowicz@ucsb.edu>, Maxime Lefrançois <maxime.lefrancois@emse.fr>, SDW WG Public List <public-sdw-wg@w3.org>
Message-ID: <fc51c5df-e372-ddfb-e8af-00c54083163d@w3.org>


On 02/02/2017 23:50, Kerry Taylor wrote:
> Ø  5.c. I really thought what we commonly mean by backward compatibility is that I wouldn't even need to change the prefix declaration ? I thought the old SSN namespace will redirect to the IRI of the ontology document that is backward compatible with the old SSN ?
>
> That’s the plan – as it was suggested by Phil who also explained that it can be done from a W3C perspective and purl perspective. Is this controversial and needs a vote? I would be happy to take an ACTION, but I thought this would be a very late step  in our process so as to not force people to use their  current ssn while it is still unstable.

I did say that, yes. However, it seems to me that the understandable 
desire to build on previous implementation is so skewing the discussion 
that it is damaging. I would feel a lot more comfortable if we all-but 
forgot about old SSN for now, and then come back to it once the 
overriding issues have been resolved.


>
> Ø  We also revisited the name SOSA over and over again, lets not reopen this discussion.
>
>
>
> Ahhhhh,  I beg to differ.. It was something that was declared decided many times when it was questioned, but that does not make it decided.  The question has in fact never been asked, let alone revisited, despite the fact that I asked it to be discussed and despite the fact that several people have expressed some concern with “SOSA” (and I am not going to speak for their opinions.)   Can you point please to some evidence that it was decided? And note that I asked it to be dicsussed well before it was written into the current WD, without discussion, so I’m just covering here for a possible statement  that  we all agreed with the evidence that it is in the current WD that we voted for.
>


My evidence that the name SOSA was agreed upon, and that it provides a 
lightweight core beyond which SSN provides more detail, is the document 
published with the consent of the whole WG

https://www.w3.org/TR/2017/WD-vocab-ssn-20170105/

in which I find:

"The Sensor, Observation, Sample, and Actuator (SOSA) ontology is one of 
the modules provided by the Semantic Sensor Network ontology. It acts as 
the core building block of SSN around which all other classes and 
relationships evolve."



>
>
> Btw “ssn core” has been proposed. I’m quite fond of the  “ssn light” idea or better still “ssn lite?”
>
> Ø  This is where the trouble starts. SOSA and SSN are *not*
> incompatible. Kerry will of course state this over and over again but
> this does not make it true.
>
> Its ok my skin is getting very thick here – I will not take the offence that, frankly, looks rather intended.
>
> Kerry
>
>
> From: Krzysztof Janowicz [mailto:janowicz@ucsb.edu]
> Sent: Friday, 3 February 2017 5:39 AM
> To: Maxime Lefrançois <maxime.lefrancois@emse.fr>; SDW WG Public List <public-sdw-wg@w3.org>
> Subject: Re: State of SSN: arguments in favour of a single name and namespace, proposal, the SEAS example, proposal of action
>
> Hi Maxime,
>
>
> 2.a Well I'm just telling you how I actually felt. You cannot disagree with the fact that I felt this way.
> 2.b On the other hand, I know you and Armin were not very happy with the name SOSA itself. Is SOSA some kind of brand you want to keep ? Wouldn't it be acceptable for you to rename it "SSN Vocabulary", or "SSN Light Profile" ?
> 2.c So to put it simply, instead of simplifying something that exists and is too complicated, we rather add something new. Is that it ?
>
>
> I am not disagreeing with your feelings but with the interpretation about being twice as complex :-).  Btw, I am happy with the name SOSA and Armin also supports it. This must be a misunderstanding. We also revisited the name SOSA over and over again, lets not reopen this discussion.
>
>
> 5.a Here again, I'm just telling you how I feel. My fears and hope. That's not a scientific argument, but other potential users may feel the same.
> 5.b It depends on how you define "incompatible". SOSA adopts new names for the same concepts that were there before, and sometimes new definitions. You could say it's just *new* and unrelated to SSN (and compatible with it therefore). But from my point of view, what I see is there may be issues.
> 5.c. I really thought what we commonly mean by backward compatibility is that I wouldn't even need to change the prefix declaration ? I thought the old SSN namespace will redirect to the IRI of the ontology document that is backward compatible with the old SSN ?
> 5.d Actually, I personally don't really care about point 5.c, the SEAS ontologies already import the new https://www.w3.org/ns/ssn/ namespace. It could be problematic for some hypothetical legacy system that uses the old namespace and ontology axioms though.
>
> I am not arguing about your feelings but making arguments that your old work is still valid as old-SSN has not changed.  New-SSN will differ in many regards from old-SSN because we have changed axioms and also removed many, many of them. This may or may not affect your specific ontology and data depending on whether you made use of these parts of SSN or not. New-SSN and old-SSN entailment differs.  New-SSN has its own new namespace. The existence of SOSA does not affect your data at all.
>
> Cheers,
> Jano
>
>
>
> On 02/02/2017 10:30 AM, Maxime Lefrançois wrote:
> Hi Jano,
>> -1 for SOSA and SSN having the same namespace
>
> Sorry, see my answer to Kerry, this is an unfortunate typo:
>
> -1 for SOSA and SSN having separate namespaces
> +1 for SOSA and SSN having the same namespace.
>
>
>>  1. Communication-wise, and as a WG member, I would argue that a
>> single namespace and a single name "SSN" demonstrates that the group
>> is unified, whereas 2+ namespaces and 2+ names (SSN and SOSA)
>> demonstrates the group is split in two. This is my impression and
>> could the the impression of other people exterior to the group.
>
> I think this is really a misunderstanding of namespaces. The SDW will
> also use different namespaces and nobody would argue that we are not
> unified simply because TIME and SSN do not share a common namespace.
>
> 1.a TIME and SSN talk about different domains. They where introduced in different documents, by different people. That's a historic difference.
>
> 1.b SSN and SOSA talk about the same domain. I strongly believe that using two different namespaces brings more confusion, and less usability, contrary to what has been said before. Let me just point to a recent email on this list [1]:
>  - Phil: What's the difference between sosa:hosts and sosa:attachedSystem ? Do we need both?
>  - Jano: SOSA should not have an attachedSystem relation. Do you mean SSN?
>
> If choosing what prefix should be used for ***:attachedSystem is even unclear to WG members that are highly involved such as Phil, how do you expect the lambda user not to be confused ?!?
>
>
>>  2. Name-wise, as a user of the SSN ontology, I actually expect that
>> the outcome of this group is a simplified SSN. The name "SSN" is known
>> to me. So when I see there is now SOSA *and* SSN, I think the outcome
>> of the group is twice as complex that it was before. This is discouraging.
>
> I absolutely disagree with this statement and I cannot follow your
> argumentation. The SOSA is something new, this has nothing to do with
> SSN being known. We are not taking SSN away in any. That said, the new
> SSN is going to be pretty different from the old SSN so maybe it is good
> to make this very clear in all possible ways we can.
>
> 2.a Well I'm just telling you how I actually felt. You cannot disagree with the fact that I felt this way.
> 2.b On the other hand, I know you and Armin were not very happy with the name SOSA itself. Is SOSA some kind of brand you want to keep ? Wouldn't it be acceptable for you to rename it "SSN Vocabulary", or "SSN Light Profile" ?
> 2.c So to put it simply, instead of simplifying something that exists and is too complicated, we rather add something new. Is that it ?
>
>
> 3. You did not comment on argument 3 does this mean you accept it ?
>
>
> 4. You did not comment on argument 4 does this mean you accept it ?
>
>
>>  5. On a very personnal level, I spent much effort making so that the
>> SEAS ontologies use the SSN terms properly, and are compatible with
>> the SSN ontology. I have been quite discouraged when I saw that new
>> name "SOSA", and all the incompatibilities that seemed to arise with
>> SSN. I was afraid it would ruin my efforts in being compatible with
>> the SSN ontology. The SEAS ontologies are an example of usage of the
>> SSN ontology, and I really hope they will remain compatible with the
>> new SSN.
>
> Maxime. This is where the trouble starts. SOSA and SSN are *not*
> incompatible. Kerry will of course state this over and over again but
> this does not make it true. That said, new-SSN is not the same as
> old-SSN so you may have to revisit your ontology if you want to remain
> compatible with the new SSN which has a new URL as well so your old work
> using the old SSN is *not* damaged in any way.
>
> 5.a Here again, I'm just telling you how I feel. My fears and hope. That's not a scientific argument, but other potential users may feel the same.
> 5.b It depends on how you define "incompatible". SOSA adopts new names for the same concepts that were there before, and sometimes new definitions. You could say it's just *new* and unrelated to SSN (and compatible with it therefore). But from my point of view, what I see is there may be issues.
> 5.c. I really thought what we commonly mean by backward compatibility is that I wouldn't even need to change the prefix declaration ? I thought the old SSN namespace will redirect to the IRI of the ontology document that is backward compatible with the old SSN ?
> 5.d Actually, I personally don't really care about point 5.c, the SEAS ontologies already import the new https://www.w3.org/ns/ssn/ namespace. It could be problematic for some hypothetical legacy system that uses the old namespace and ontology axioms though.
>
> -----
>
> I won't go any further in the exponential growth of arguments.
>
> Best,
> Maxime
>
> [1] https://lists.w3.org/Archives/Public/public-sdw-wg/2017Feb/0018.html
>
>
>
>
> --
>
> 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/
>
> Semantic Web Journal: http://www.semantic-web-journal.net
>

-- 


Phil Archer
Data Strategist, W3C
http://www.w3.org/

http://philarcher.org
+44 (0)7887 767755
@philarcher1
Received on Friday, 3 February 2017 10:51:25 UTC

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