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Re: RDFa, RDF Collection Semantics and Temporal RDF

From: Gregg Kellogg <gregg@greggkellogg.net>
Date: Sat, 29 Dec 2012 16:34:15 -0500
To: Adam Sobieski <adamsobieski@hotmail.com>
CC: "public-rdfa@w3.org" <public-rdfa@w3.org>
Message-ID: <0EFDC527-2274-4DF5-AC6E-EAD3CAECDDEC@greggkellogg.net>
On Dec 29, 2012, at 10:21 AM, Adam Sobieski <adamsobieski@hotmail.com> wrote:

> RDFa Working Group,

Hi Adam,

> Greetings. I would like to broach for discussion RDFa and some hypertext document scenarios including RDF collections, Containers And Collections (http://www.w3.org/2010/02/rdfa/wiki/ContainersAndCollections) and time-based multimedia documents or documents with time-based multimedia components, with RDF semantics. Some topics are discussed at Introducing Time into RDF(http://www.cs.rpi.edu/~willig4/temp/time.pdf) and other topics include SMIL-based container and collection semantics.
> Are the ideas discussed in Containers and Collections post-conceptual or in a phase towards specification, for example in HTML + RDFa 1.1 (http://www.w3.org/TR/rdfa-in-html/)? 

RDFa Core 1.1 has support for RDF Collections via use of the @inlist attribute. This allows, for example, the following Turtle to be represented in RDFa fairly easily:

[] a :FiniteListOfNumbers;  rdf:value ("one" "two" "three") .

Using HTML such as the following:

<ol typeof="FiniteListOfNumbers">
  <li inlist property="rdf:value">one</li>
  <li inlist property="rdf:value">two</li>
  <li inlist property="rdf:value">three</li>

RDF Containers (such as rdf:Seq and rdf:Bag) are close to deprecation, and are considered _archaic_ in RDF 1.1 [1], so don't look for any syntactic support to be added for them.

> Argumentation and RDFa is an interesting topic (http://lists.w3..org/Archives/Public/public-argumentation/2012Dec/0000.html) and an example usage scenario, with regard to the topics under discussion, is that of digital mathematics textbooks utilizing RDFa for the semantics of mathematical proofs in hypertext-based documents which explain mathematical proofs didactically. Towards complex document structure topics, some mathematical concepts might have multiple mathematical proofs and some mathematical proofs or mathematical proof portions might have multiple discussions, for example for different learning styles. Navigation can be facilitated by techniques including tab-based ergonomics or multitouch. The mathematical proofs' semantics can be represented in such hypertext-based document scenarios utilizing, perhaps, RDF containers and collections.
> Additionally, time-based multimedia documents and documents with time-based multimedia components are interesting topics with regard to hypertext-based documents, digital books and textbooks, and RDFa (http://lists.w3.org/Archives/Public/public-html/2012Dec/0118.html), for example infographics.

Time-based information is indeed interesting. IMO, this is a good use case for Named Graphs [2], as anything else looks like Reification; a concept which is also becoming archaic. If there is an RDFa 2.0 (or 1.2), I would expect to see support for named graphs to be included. It's being included in JSON-LD[3] to support similar use cases.

> Kind regards,
> Adam Sobieski


[1] http://www.w3.org/2011/rdf-wg/track/issues/77
[2] http://www.w3.org/TR/rdf11-concepts/#dfn-named-graph
[3] http://json-ld.org/spec/latest/json-ld-syntax/index.html#named-graphs
Received on Saturday, 29 December 2012 21:34:58 UTC

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