- From: Irene Polikoff <irene@topquadrant.com>
- Date: Sun, 17 Apr 2016 13:47:19 -0400
- To: <kcoyle@kcoyle.net>
- CC: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
With respect to graphs, is something like this better? RDF graph containing triples that represent shapes is called ³shapes graph². Or A set of triples representing shapes is called a ³shapes graph². I am not certain what is the exact nature of the comprehension/clarity problem here because I, for example, don¹t quite understand what the sentence below means and the issues it is trying to highlight: "It seems to me that a graph may have sub-graphs, and the subjects of those may be instances of classes, but it's gotta be triples all the way down.² What does it mean for a graph to have sub-graphs and, even more importantly, why do we care? What are ³those² in the ³subjects of those²? Are they sub-graphs as in ³the subjects of sub-graphs²? If so, what are ³the subjects of sub-graphs²? Irene Polikoff On 4/17/16, 10:46 AM, "Irene Polikoff" <irene@topquadrant.com> wrote: >Then, you should write something that works for you and see what others >think of it. > >Once you move outside of very basic topics, judging clarity of language >becomes very subjective. For any paragraph that seems perfectly clear to >some, there will be others who'd find it inadequate in some way. > >Sent from my iPhone > >> On Apr 16, 2016, at 11:28 PM, Karen Coyle <kcoyle@kcoyle.net> wrote: >> >> That doesn't work for me, because once again we have no definition of >>"shape" other than saying that it is an instance of sh:Shape, which >>makes it an instance of a class, and, AFAIK, an instance of a class >>cannot "point to" anything. I'm also pondering how a graph can contain >>instances of classes. It seems to me that a graph may have sub-graphs, >>and the subjects of those may be instances of classes, but it's gotta be >>triples all the way down. This seems to be a mixing of structure and >>semantics. For now, let's get the triples well-defined, and then we can >>worry about the semantics of classes. >> >> kc >> >>> On 4/16/16 7:35 PM, Irene Polikoff wrote: >>> I think it is quite simple: >>> >>> * A SHACL shape is an instance of sh:Shape. A shape points to >>> constraints (or conditions) an RDF node is compared against to >>> determine if it conforms to the shape. For example, a shape >>> example:Issue may point to two constraints: one that says that the >>> property example:submitter must have exactly one value and the value >>> must be a string and one that says that the property >>> example:submissionDate must have exactly one value and the value >>> must be a date. >>> * When an RDF node conforms to conditions specified by a shape it is >>> said to be valid against a shape. >>> * A shape can also define what RDF nodes are to be validated (checked >>> for conformance) against it. This is called a scope of a shape. When >>> a shape doesn¹t specify a scope, its scope is any RDF node. >>> >>> The specification also uses the following terminology: >>> >>> * RDF graph containing shapes is called ³shapes graph². >>> * RDF graph containing data to be checked for conformance (validated) >>> is called ³data graph². >>> * When examples talk about specific nodes that are being checked >>> against a shape, they use a term ³focus node². >>> * A report produced as a result of checking RDF data against the >>> relevant shapes is called a "validation report". >>> >>> >>> >>> Irene Polikoff, CEO >>> TopQuadrant, Inc. www.topquadrant.com <http://www.topquadrant.com/> >>> Technology providers making enterprise information meaningful >>> Blogs ‹ http://www.topquadrant.com/the-semantic-ecosystems-journal/, >>> http://www.topquadrant.com/composing-the-semantic-web/ >>> LinkedIn ‹ https://www.linkedin.com/company/topquadrant >>> Twitter - https://twitter.com/topquadrant >>> >>> >>> >>> >>> >>> On 4/16/16, 4:49 PM, "Karen Coyle" <kcoyle@kcoyle.net >>> <mailto:kcoyle@kcoyle.net>> wrote: >>> >>> I decided to take Peter's request that more people read through the >>> document, figuring that I would only be able to do a portion of it >>> before it got over my head. However, I haven't gotten very far due >>>to >>> what I presume is some of that lack of consistency that Peter has >>> mentioned. >>> >>> The introduction (1.) has these sentences: >>> >>> "SHACL groups descriptive information and constraints that apply to >>>a >>> given data node into shapes. This document defines what it means >>>for an >>> RDF graph, referred to as the "data graph", to conform to a graph >>> containing SHACL shapes, referred to as the "shapes graph"." >>> >>> "A shape may include a scope which defines which nodes in the data >>> graph >>> must conform to it. When a data node is checked for conformance to a >>> shape, that node is referred to as the focus node. The output of the >>> validation process is a validation report which indicates whether or >>> not >>> the data graph conforms to the shapes graph." >>> >>> In these we have "shapes", "SHACL shapes", "shapes graph", "nodes", >>> "data nodes" "focus nodes". >>> >>> Shortly thereafter we have "shape definitions", and a "shapes graph >>> that >>> defines these constraints has two shapes." >>> >>> The main problem is the use of "shape/shapes" some times and "shapes >>> graph" at others, with the implication (but not stated) that a >>>"shapes >>> graph" can consist of one or more "shapes." However, I'm not sure >>> what a >>> shape is in this context, since it is by definition in the form of a >>> graph. >>> >>> Note also that the examples in that section consist of multiple >>>graphs, >>> that is there is no subject that holds them together. I believe they >>> should have a symbolic "top node" that shows that they belong to a >>> single graph even though there are subgraphs. >>> >>> I'm happy to write alternate text for some of this, but in this case >>> I'm >>> not clear on what is intended. >>> >>> There are other areas where I can suggest better wording. I'd >>>rather do >>> edits in a copy than try to explain them. Would that be ok? >>> >>> kc >>> >>> -- >>> Karen Coyle >>> kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net >>> m: 1-510-435-8234 >>> skype: kcoylenet/+1-510-984-3600 >> >> -- >> Karen Coyle >> kcoyle@kcoyle.net http://kcoyle.net >> m: 1-510-435-8234 >> skype: kcoylenet/+1-510-984-3600 >>
Received on Sunday, 17 April 2016 17:47:56 UTC