- From: Guus Schreiber <guus.schreiber@vu.nl>
- Date: Wed, 8 Jan 2014 11:26:04 +0100
- To: Thomas Baker <tom@tombaker.org>, RDF Working Group <public-rdf-wg@w3.org>
Tom, Thanks for the extensive review, very helpful! We will get back to you with a detailed response. Best, Guus On 08-01-14 05:19, Thomas Baker wrote: > The Primer [1] is taking shape nicely! > > Bob DuCharme and Antoine Isaac have already raised alot of excellent points > [2,3]. The comments below are divided into comments of substance, comments > specifically about the NOTEs, and copyediting suggestions. > > I agree with Antoine that we should take the opportunity to help make it > perfect...! :-) > > Tom > > [1] http://lists.w3.org/Archives/Public/public-rdf-comments/2013Dec/0124.html > [2] https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-primer/index.html# > [3] http://lists.w3.org/Archives/Public/public-rdf-comments/2014Jan/0006.html > > ====================================================================== > Comments of substance > > -- "The Resource Description Framework (RDF) is a framework for describing > information about resources..." > > This definition uses the same three words as what it defines -- Resource, > Description, and Framework. How about: > > The Resource Description Framework (RDF) is a language for expressing > information about things. > > -- "...about resources in the World Wide Web" > > Do we want to project the message that RDF is really just about describing > Web pages and videos? > > Paragraph three starts with "In particular, RDF can be used to publish and > interlink data on the Web" -- and IMO paragraph three is the right place to > make this connection. > > I suggest dropping the second half of the first sentence and substituting > it with a sentence or two to the effect that RDF is a language for data > which uses Web addresses as globally defined names for things and leverages > those global names to enable data to be connected across a multitude of > distributed, independently maintained data sources. I could propose more > polished wording if desired. > > -- "framework" -- or "language"? > > I suspect the average reader will have no concept of "framework". But if > RDF were called a "language" in the first paragraph, it could also be > called a language further down. Specifically: > > RDF allows us to make statements about resources > > could be > > RDF provides a language for making statements about resources > > -- "An RDF statement represents a relationship between two resources." > > As the text goes on to say that the subject and object _represent_ the two > resources being related and the predicate _represents_ the nature of their > relationship, it seems more precise to say: > > An RDF statement states a relationship between two resources. > > -- "Resources typically occur in multiple triples" > > This wording seems problematic because further down on that page, the text > lists IRIs, literals, and blank nodes as things that "occur in triples". > How about: > > Resources, such as "Bob" and "The Mona Lisa", are typically the subject > or object of multiple triples. > > -- "Informally speaking, RDF allows us to make statements of the form:" > > What is informal here is not the fact that RDF allows us to make three-part > statements, but the informal syntax used to present them. How about: > > RDF allows us to make three-part statements such as the following > (expressed here, for readability, in pseudocode): > > Maybe there is a better word for it than pseudocode, though I think it > sort of works. > > -- Section 3.2 on IRIs in triples > > The text _says_ that IRIs can appear in all three positions, but it only > provides example IRIs for a subject (The Mona Lisa) and an object > (Leonardo). Perhaps the section could go one step further and introduce > the IRI for the property foaf:topic_interest (without waiting for Section > 5.1). Then it could show the triple: > > <http://www.wikidata.org/entity/Q12418> > <http://xmlns.com/foaf/0.1/topic_interest> > <http://dbpedia.org/resource/Leonardo_da_Vinci> > > -- Section 3.3 on Literals > > The use of literals could then be illustrated with: > > <http://www.wikidata.org/entity/Q12418> > <http://purl.org/dc/terms/title> > "Mona Lisa" > > -- Section 3.4 on Blank Nodes > > I agree with Bob that this section is too brief and should either be > dropped (please not!) or expanded, perhaps with a diagram. > > If RDF were called a language from the start, then blank nodes could > be explained by analogy to subordinate clauses. For example: > > Bob is interested in something which has the title "The Mona Lisa". > > Trying to express this in the pseudocode of section 3 seems inadequate: > > <Bob> <is interested in> <X> > <X> <has the title> <The Mona Lisa> > > However, if the use of IRIs and literals in triples has just been > illustrated in the previous two sections, one could posit, for the sake of > argument that one does not know a URI for "Mona Lisa" and say: > > <http://example.org/bob#me> > <http://xmlns.com/foaf/0.1/topic_interest> > :blank_node_id1 > > :blank_node_id1 > <http://purl.org/dc/terms/title> > "Mona Lisa" > > The accompanying diagram could be an adaptation of Figure 2. > > -- "For both classes and properties one can create subtype hierarchies". > > Read in the context of the previous sentence ("The relation between an > instance and its class is modelled through the type property"), this could > be taken to mean that classes and properties can be sub-classed. How > about: > > One can create create hierarchies of classes and sub-classes or of > properties and sub-properties. > > Also (s/modelled/stated): > > The relation between an instance and its class is stated using the > type property. > > -- "Type restrictions on the subjects and objects of particular triples can be > defined through domain respectively range restrictions" > > This could be read as meaning that domain and range can be used to > "restrict" values in a closed-world sense. Also, domains and ranges are > not defined for "particular triples" but for properties. Maybe something > like (to be improved): > > The types of resources associated with a given property in the context > of statements can be specified with a domain (for subjects) and range > (for objects). > > It might be worth drawing this out a bit by emphasizing that domains and > ranges are about making inferencing possible, if it could be done briefly > and illustrated with a nice example. > > ====================================================================== > The use of NOTEs > > The NOTE blocks make good points but at the cost of interrupting the flow > of the text. Calling out NOTEs as separate blocks has the effect of > drawing attention to the sort of detail I'd expect to find in footnotes. > Taking them note by note: > > "This primer is..." > > Maybe put in a separate, unnumbered section before the Introduction > called "About this document"? > > "An IRI is..." > > The notion that RDF uses IRIs as names for things is so fundamental > that it should be introduced in the first paragraph or two. That > explanation could already state the relationship of IRIs to URIs and > URLs (as per section 3.2 and Bob's comments thereon). Such an expanded > explanation would replace this NOTE. > > "The RDF Data Model..." > > That the RDF Data Model is expressed with an abstract syntax which is > independent of a particular [concrete syntax] is also a really key > point. The notions "abstract syntax" and "concrete syntax" could > perhaps be defined in the Introduction by re-casting the list of > normative specifications as a list of things provided by the suite of > specs, e.g.: > > The normative specifications of RDF define: > > * The RDF Data Model, with an abstract syntax independent of any > particular concrete syntax ("RDF Concepts and Abstract Syntax") > [RDF11-CONCEPTS] > > * Formal model-theoretic semantics ("RDF Semantics")[RDF11-MT] > > * Several compatible concrete syntaxes -- different ways to > record RDF data in files for processing by applications: > > ** Turtle... > ** JSON-LD... > ... > > * A data-modeling vocabulary, RDF Schema [RDF11-SCHEMA]. > > "RDF is agnostic..." > > Drop as a NOTE and fold into the explanation of IRIs in the Introduction. > > "The RDF data model assigns the special datatype rdf:langString..." > "The 2004 version of RDF contained the notion of a 'plain literal'..." > > Drop as NOTEs -- IMO these points are too detailed for the Primer. > > "The IRI associated with the graph..." > "RDF provides no way to convey this semantic assumption..." > "Multiple graphs are a recent extension of the RDF data model..." > > Drop as separate NOTEs and fold into the paragraph which starts with > "RDF 1.1 doesn't prescribe any specific semantics for datasets". > > "The syntactic form... is in a prefix notation..." > > Drop as a separate NOTE and fold into the explanation of IRIs in the > Introduction. > > The remaining notes could similarly be folded into the text. If the > content of the notes is too important to drop, perhaps the notes could all > be collected at the end as end notes. > > ====================================================================== > Copyediting suggestions > > -- "Web" and "web": Both are used. I suggest "Web", but either way, usage should be consistent. > > -- s/standard-compliant/standards-compliant/ (see http://en.wikipedia.org/wiki/Standards-compliant) > > -- "The format of these statements is simple. It always has the following form:" > > The use of "format" and "form" seems inconsistent, and the second sentence > could perhaps simply be dropped, leaving just: > > The form of these statements is simple: > > -- "visualise": does W3C still officially prefer American spelling ("visualize")? > > -- "domain respectively range restrictions": This is an odd use of "respectively". "Or"? >
Received on Wednesday, 8 January 2014 10:26:35 UTC