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

On Sep 4, 2012, at 12:09 PM, Luc Moreau wrote:

> Hi Tim,
> 
> I agree with your example.
> 
> We could add it, preceded by the following sentence:
> 
> Two different entities MAY have the same value for the attribute prov:value. For instance,
> when two entities, with the same prov:value, are generated by two different activities, as illustrated
> by the following example.
> <<Tim's example to add here>>


If you feel that the example helps your "direct representation" definition, it seems fine to add it.

I wouldn't emphasize the "by two different activities" and instead focus on the distinctiveness of the influencing entities (as I had <tweet_235> owl:differentFrom <intranet_page> .)

-Tim


> 
> Thoughts?
> Luc
> 
> On 04/09/12 16:58, Timothy Lebo wrote:
>> 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
>>> 
>> 
> 
> -- 
> 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
>