W3C home > Mailing lists > Public > public-rdf-wg@w3.org > September 2012

Re: life without dataset semantics

From: Sandro Hawke <sandro@w3.org>
Date: Wed, 19 Sep 2012 10:02:12 -0400
Message-ID: <5059D064.1090306@w3.org>
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
CC: David Wood <david@3roundstones.com>, "public-rdf-wg@w3.org Group WG" <public-rdf-wg@w3.org>
On 09/19/2012 09:48 AM, Peter F. Patel-Schneider wrote:
> I'm not convinced that there is any need to restrict properties like 
> sendCorrectionsTo to datasets.

How else could you define/document it?     In writing the property 
documentation, I find myself needing some way to talk about those 
intended triples (the ones containing the information that the 
corrections are about).  Without a dataset or some global relation 
underlying dataset semantics, I don't know how to do that.

     -- Sandro

> peter
> On 09/19/2012 09:40 AM, Sandro Hawke wrote:
>> On 09/19/2012 09:13 AM, Peter F. Patel-Schneider wrote:
>>> What do you think that the minimal semantics will get you?
>> I'm kind of in the crossfire here.   I'm not arguing for the minimal 
>> semantics.   I'm happy with no semantics/any semantics, as long as I 
>> can do my sendCorrectionsTo example (quoted below).   In my 
>> implementation work in the spring I came to the conclusion that all I 
>> need to implement all the GRAPHS use cases that I understood was the 
>> ability to define predicates like that.
>>> So far, I've heard only one thing.  If g1 and g2 denote the same 
>>> thing, then their graphs, if any, are put together (in essence). 
>>> However, you can't do much of that kind of inference in RDF, so I 
>>> don't think that there is much gain here.
>>> In the example below, it seems to me that you can proceed exactly 
>>> the same with the minimal dataset semantics, with no semantics at 
>>> all, and with the entailment-only semantics.
>> You're probably right.    There are just semantic bits in defining 
>> sendCorrectionsTo that I'm kind of confused about, like whether it 
>> makes sense to define an RDF property that only has meaning when it's 
>> used in a dataset.   That's a little weird; maybe there's a better 
>> way to define it?
>>        -- Sandro
>>> peter
>>> On 09/18/2012 07:22 PM, Sandro Hawke wrote:
>>>> So, elsewhere you're proposing we not have dataset semantics.   I 
>>>> think I'm okay with that, if I can still do what I'm trying to do 
>>>> here.      What I'm not entirely clear on is how I can do this 
>>>> without any semantics....
>>>> On 09/18/2012 02:10 PM, Peter F. Patel-Schneider wrote:
>>>>>> Here's a much better example, because it stays away from Web stuff:
>>>>>>     <g1> eg:sendCorrectionsTo <mailto:sandro@w3.org>.
>>>>>>     <g1> { w3c:group35462 rdfs:label "SPARQL Working Group" }.
>>>>>>     <g2> eg:sendCorrectionsTo <mailto:ivan@w3.org>.
>>>>>>     <g2> { w3c:group44350 rdfs:label "RDFa Working Group" }.
>>>>>> There's an obvious meaning to the predicate eg:sendCorrectionsTo, 
>>>>>> but how do I express that meaning? Something like:
>>>>>>     X eg:sendCorrectionsTo Y
>>>>>>         Note: only meaningful inside a dataset which has a named 
>>>>>> graph with
>>>>>>         the name X.
>>>>>>         Meaning: Y is a good email address for sending 
>>>>>> corrections to the
>>>>>>         information in the named graph X.
>>>>>> Are you comfortable with that?
>>>>> I don't know if comfortable is the right word.  I don't have 
>>>>> problems with anyone wanting to do that.
>>>> My question is really: do you think that definition/documentation 
>>>> means what I want it to and will work the way I want it to, if the 
>>>> RDF WG doesn't give Datasets any semantics?
>>>> That is, if the WG doesn't say anything about graph-name URIs 
>>>> connecting to URIs as used in the default graph, can I just spell 
>>>> all that out (as above) in the documentation of my predicate?
>>>> And if I can't, then what alternative do I have for sharing this 
>>>> kind of information structure?
>>>>>   I can see that if this is the stance that someone wants to take 
>>>>> with respect to named graphs, then one might want to have the 
>>>>> relationship between IRIs and graphs work the way it works in the 
>>>>> minimal semantics.
>>>>> However,  I don't think that everyone wants to have this connection.
>>>> What I'm asking for is an extremely weak connection; it's hard for 
>>>> me to see how it would do any harm, since it would only come into 
>>>> play when someone ask for it.
>>>>       -- Sandro
Received on Wednesday, 19 September 2012 14:02:27 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 22:02:07 UTC