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Re: Comments on 17 December 2013 WD of RDF 1.1 Primer

From: Guus Schreiber <guus.schreiber@vu.nl>
Date: Wed, 8 Jan 2014 11:26:04 +0100
Message-ID: <52CD27BC.6030401@vu.nl>
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

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