- From: Irene Polikoff <irene@topquadrant.com>
- Date: Sun, 17 Apr 2016 08:46:00 -0600
- To: kcoyle@kcoyle.net
- Cc: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
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 doesn’t specify a scope, its scope is any RDF node. >> >> The specification also uses the following terminology: >> >> * RDF graph containing shapes is called “shapes graph”. >> * RDF graph containing data to be checked for conformance (validated) >> is called “data graph”. >> * When examples talk about specific nodes that are being checked >> against a shape, they use a term “focus node”. >> * 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 14:46:31 UTC