Re: "property values"

Ay! Much worse than I thought - I was just looking at that one 
definition. I don't know what to do at this point.

kc

On 10/4/16 12:43 AM, Dimitris Kontokostas wrote:
> Hi Karen and thanks for this
>
> some comments inline
>
> On Tue, Oct 4, 2016 at 12:56 AM, Karen Coyle <kcoyle@kcoyle.net
> <mailto:kcoyle@kcoyle.net>> wrote:
>
>     There are 6 instances of the use of "property values" in the SHACL
>     spec. From my research, I do not believe that RDF supports the
>     concept that properties have values (unlike, for example, key/value
>     pair models). The object of a triple may have a literal value, but
>     that is not what is intended here.
>
>
> Actually there are a few hundrends, as a convention the spec uses a lot
> the term "value" and links to the property value definition.
>
>
>     Here are my suggestions for changes, in the order in which they
>     appear in the document:
>
>     1 Now reads in the terminology section:
>     "Property Values and Paths
>     The values of (or for) a property p for a node n in an RDF graph are
>     the objects of the triples in the graph that have n as subject and p
>     as predicate."
>
>     This could become "Object nodes" but in fact I think that "node n"
>     here is referring to the subject node? Not sure. I would define
>     "object nodes" and "property paths" separately, and the latter
>     definition could be copied from SPARQL. In fact, it might be good to
>     reference the SPARQL documentation at this point.
>
>
> For simple properties object values is correct but for paths the node
> might also be a subject node since we allow inverse relations.
> The spec already reuses part of the SPARQL definition for property paths
> and splitting the terms sounds good to me
> https://www.w3.org/TR/sparql11-query/#propertypaths
>
>
>
>     2 Now reads:
>     "Some of the property constraints specify multiple constraint
>     components in order to restrict multiple aspects of the property
>     values."
>
>     I have no idea what "multiple aspects of the property values" means
>     here. I think this sentence and the two that follow it should be
>     changed to something like:
>     "There can be multiple constraints directed at a single node."
>
>     3&4 drop
>
>     5 now reads:
>     "It is a common scenario that certain property values are derived
>     from other values. "
>
>     In the RDF documentation, "value" is used exclusively with literals.
>     If this is the case here, then it may be appropriate to refer to
>     "literals" or "literal nodes" (which by definition includes only
>     object nodes) rather than property values.
>
>
> Looking at R2RML the term value is also used for non-literals but the
> wording there is a little more verbose without needing a definition
> https://www.w3.org/TR/r2rml/#foreign-key
>
> Dimitris
>
>
>
>     kc
>     --
>     Karen Coyle
>     kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net
>     m: 1-510-435-8234
>     skype: kcoylenet/+1-510-984-3600 <tel:%2B1-510-984-3600>
>
>
>
>
> --
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig & DBpedia Association
> Projects: http://dbpedia.org, http://rdfunit.aksw.org,
> http://aligned-project.eu
> Homepage: http://aksw.org/DimitrisKontokostas
> Research Group: AKSW/KILT http://aksw.org/Groups/KILT
>

-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600

Received on Tuesday, 4 October 2016 12:35:46 UTC