Re: PROV-ISSUE-449: Better definition of prov:value [prov-dm]

Luc,

On Sep 4, 2012, at 11:42 AM, Luc Moreau wrote:

> Hi Tim and Jim,
> 
> Do you want to make a suggestion for a definition of prov:value?
> 
> I see prov:value as the equivalent of "immediate operands" in assembly language :
> "An operand that is directly encoded as part of a machine instruction is called an immediate operand. [1] "
> 
> So, to get the ball rolling, attempting a definition:
> prov:value is an attribute whose value is a direct representation of an entity as a PROV-DM Value(5.7.3).


I think this definition is much better. "direct representation" conveys it well and I think is satisfactory.


Some nit-picking that shouldn't hold us up:

Informatively, where do you see prov:value fitting with prov:specializationOf and inverse functionality?

It seems that the following two entities could be distinct, where one distinguishing aspect is their "source":

:quote_1
    prov:value "Four score and seven years ago";
    prov:wasQuotedFrom <tweet_235>;
.

:quote_2
   prov:value "Four score and seven years ago";
   prov:wasQuotedFrom <intranet_page>;
.

<tweet_235> owl:differentFrom <intranet_page> .
:quote_1 owl:differentFrom :quote_2 .


Does "Directly represented" imply a degree of inverse functionality? I don't think it should, but it seems to.


Regards,
Tim







> 
> Cheers,
> 
> Luc
> 
> 
> [1] http://chortle.ccsu.edu/assemblytutorial/Chapter-11/ass11_2.html
> 
> On 17/07/12 17:01, Timothy Lebo wrote:
>> Graham noted in his prov-o review [1]:
>> 
>> [[[
>>  But, maybe more fundamentally, is there any specified way to express a value that is itself denoted by a URI?  
>>  In OWL terms, this needs an object property. It's OK if ther4e's no such way, as one can always introduce new properties, 
>>  but it seems odd to me that data values are OK but other values are not.
>> ]]]
>> 
>> 
>> 
>> After discussing this with Jim McCusker, I'm convinced that prov:value is the literal analogue to prov:specializationOf.
>> 
>> In:
>>       :my_calculation_result prov:value 4.5 .
>> 
>> or
>>        :my-copied-test prov:value "For score" .
>> 
>> Both subjects _are_ specializations of their objects, and their objects have relatively few fixed aspects (abstract mathematical relationship, a string length, etc).
>> 
>> 
>> 
>> I'm not sure if we want to mix prov:specializationOf into the discussion of prov:value, but this ISSUE is about the need for a clearer definition of prov:value.
>> 
>> Also, I think the answer to Graham's question is "we have a way to express a value of a URI - prov:specializationOf".
>> 
>> 
>> Thanks,
>> Tim
>> 
>> 
>> 
>> 
>> 
>> [1] http://www.w3.org/2011/prov/wiki/Review_of_prov-o_july_3_2012_for_last_call#Graham
>> 
>> 
>> 
>> On Jul 9, 2012, at 5:39 PM, Provenance Working Group Issue Tracker wrote:
>> 
>>> PROV-ISSUE-449: Better definition of prov:value [prov-dm]
>>> 
>>> http://www.w3.org/2011/prov/track/issues/449
>>> 
>>> Raised by: Timothy Lebo
>>> On product: prov-dm
>>> 
>>> Although we know that prov:value is very useful,
>>> 
>>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html#term-attribute-value
>>> 
>>> does not provide a satisfactory definition.
>>> 
>>> We are copying rdf:value: http://www.w3.org/TR/rdf-schema/#ch_value which provides an equally unsatisfying definition: 
>>> 
>>> [[[
>>> rdf:value is an instance of rdf:Property that may be used in describing structured values.
>>> 
>>> rdf:value has no meaning on its own. It is provided as a piece of vocabulary that may be used in idioms such as illustrated in example 16 of the RDF primer [RDF-PRIMER]. Despite the lack of formal specification of the meaning of this property, there is value in defining it to encourage the use of a common idiom in examples of this kind.
>>> ]]]
>>> 
>>> Can we do better?
>>> 
>>> Thanks,
>>> Tim
>>> 
>>> 
>>> 
>>> 
>>> 
>> 
> 
> -- 
> Professor Luc Moreau
> Electronics and Computer Science   tel:   +44 23 8059 4487
> University of Southampton          fax:   +44 23 8059 2865
> Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
> United Kingdom                     http://www.ecs.soton.ac.uk/~lavm
>