Re: RDF Primer Draft - comments

Antoine,

Thanks for the extensive review, very helpful!

We will get back to you with a detailed response.

Best,
Guus

On 07-01-14 23:46, Antoine Isaac wrote:
> Dear Yves, Guus, all,
>
> Trying to follow from a distance what the group is doing, I have read
> the latest editor's draft of the RDF Primer
> http://www.w3.org/TR/2013/WD-rdf11-primer-20131217/
>
> I'm not sure how well it fits your schedule, but I thought I'd share
> some comments, see below. It may overlaps or conflicts with previous
> comments from group members... I hope this can help you still.
> I find it a really great document now--which means that we should seize
> the opportunity and make it nearly perfect ;-)
>
> Best regards,
>
> Antoine
>
> ----
>
> First a general editorial comment: I like the way notes flag slightly
> less essential details. But in a text that is quite compact, having this
> many notes may be counter-productive. Perhaps a couple of them can be
> integrated in the main text, like the one on IRIs in section 1?
>
> The rest of the comments are in the order of the sections.
>
> - 1, "The Resource Description Framework (RDF) is a framework for
> describing information about resources in the World Wide Web, such as
> author and modification time of a Web page or copyright and licensing
> information of a Web video."
> With earlier comments on the group's list still in mind, I must say that
> having this sentence upfront will lead some to think that RDF is for
> document annotation. Perhaps it would be good to add a sentence that
> makes it clear that RDF can also be used for describing real-world
> entities (persons, etc.).
> In the same line, the wording 'describing information about resources'
> makes me a bit uncomfortable: how about 'describing resources' instead,
> or 'expressing information about resources' (as it is put later in the
> text)?
>
> - 1: The URI http://www.example.org/bob is potentially confusing. I am
> personally ok with it, especially as it follows the sort of examples
> we've seen in the community for years. But in the light of the
> discussion on named graphs, perhaps it would be clearer if the IRI was
> picked to intuitively denote a document or information source, rather
> than a real-world person (that is now identified by
> http://www.example.org/bob#me).
>
> - Or perhaps this problem comes from the two sentences after the one
> where Bob's URI is introduced:
> "[...]including the fact that he knows Alice, as identified by her IRI.
> Retrieving Alice's IRI [...]".
> I believe "her IRI" in the first sentence is
> http://example.org/alice#me, while reading the second sentence one could
> expect http://example.org/alice (having just being presented
> http://www.example.org/bob before).
> I'm splitting hair obviously, but I can't help thinking that we often
> use less-intuitive identifiers that make SemWeb documentation much less
> easy to read.
>
> - 2:"Providing a standard-compliant way for exchanging data between RDF
> databases."
> -> "Providing a standard-compliant way for exchanging data between
> databases."
> (as a use case, the first sentence reads a bit as if RDF had been
> motivated by the need to exchange RDF data...)
>
> - 3.2, Note on "RDF is agnostic about what the IRI stands for[...]": I'm
> not sure the reference "RDF vocabularies are discussed in more detail in
> Sec. 4." belongs there.
>
> - 3.4.: I'm not fond of the sentence "A blank node indicates an un-named
> thing." One could create a blank node for Bob, who is a named individual
> in the real world. One could even give an rdfs:label with Bob's name in
> the RDF graph with this blank node. I'd rather see the paragraph stick
> to the term 'unidentified'.
> Actually you could replace the quoted sentence by "They can be used to
> denote resources without explicitly identifying them with an IRI." and
> remove the current last sentence of 3.4.
> By the way, isn't it misleading to write "can be used to denote
> resources [...]"? Isn't it always the case? Or at least what happens in
> the vast majority of cases? (sorry, I don't have time to check whether
> I'm missing something obvious here)
>
> - 3.5: I know this section has been discussed, so perhaps my comments
> will come across as a re-hash, or going against some recent agreement on
> the text. Sorry if it's the case...
> Even though I really want something on named graphs to be said, I really
> find some points quite hard for a primer:
>
> -- "An RDF dataset may have [...] at most one default graph (i.e. a
> graph without a name).": do we really need to mention the constraint on
> the default graph, or even default graphs, in this Primer? I believe
> that the text could work well without writing about these.
>
> -- "RDF 1.1 does not specify a particular semantics for the relation
> between the "graph name" and the graph": I know the RDF group has
> discussed the issue at length, but this sentence sounds a bit like a
> joke, without any further precision the motivation.
> The issue is that the reference to [RDF11-MT,
> http://www.w3.org/TR/2013/CR-rdf11-mt-20131105/#rdf-datasets] doesn't
> really work for me: I guess the solution is in the following sentence
> there: "This allows IRI referring to other kinds of entities, such as
> persons, to be used in a dataset to identify graphs of information
> relevant to the entity denoted by the graph name IRI." But I can't parse
> it and come with a concrete example (ie., an example with realistic IRIs
> involved in realistic triples) that would show me what's at stake.
>
> -- "RDF provides no way to convey this semantic assumption [...] Those
> readers will need to rely on out-of-band knowledge to interpret the
> dataset in the intended way.": here "no way" and "out-of-band" read as
> if it is impossible to convey the assumptions in RDF at all. As you've
> discussed, it seems possible to devise appropriate vocabularies (even
> though it's outside of the standard)...
>
> -- could the last note on named graphs and SPARQL be shortened, and/or
> become part of the main text? (e.g., put in the first paragraph of the
> section)
>
> - 4: I would find it easier if the identifiers of classes and properties
> in the examples were chosen to reflect their type (i.e., "c", "c1",
> "c2", for classes, "p" for a property, "i" for an instance") rather than
> their position in the RDFS triples (currently "s" is alternatively used
> for a class, a property and an instance).
> By the way, following your convention, then the second triple should
> have been "s rdf:type rdf:Property", no?
>
> - 4: it's a bit confusing to find Wordnet in the list of "vocabularies"
> there. The elements that Wordnet defines are not directly defined as
> properties and classes in the RDFS sense, unlike the elements of DC,
> schema.org and SKOS. Shouldn't it be listed in section 7, with the other
> databases?
>
> - 5: the graphs are really beautiful, but their graphic convention could
> perhaps be further homogenized, by putting all (typed) literals within
> brackets, and "Bob" out of its circle, like Alice and Mona Lisa.
>
> - 5.3: space missing after "see Fig. 2)"
>
> - 6: the triple "ex:Species rdf:type rdfs:Class ." is not really
> necessary I think. The gist of the example is that ex:Elephant is both
> an instance and a class, not that ex:Species is a class.
>
> - 7. The reference to http://datahub.io/organization/lodcloud could
> raise problems. The Data Hub's move from 'groups' to 'organizations' and
> the fact that a dataset can be in only one organization has resulted
> many datasets disappearing from their original grouping. I'm afraid the
> same thing may have happened for the LODCloud group. The LODCloud group
> still includes RDF datasets and can be used as a source of example, but
> I believe it's not representing the most recent LOD Cloud as we know it
> at http://lod-cloud.net/state/.
>
>

Received on Wednesday, 8 January 2014 10:26:13 UTC