--- a/microdata-rdf/index.html Tue Sep 11 20:50:08 2012 -0700
+++ b/microdata-rdf/index.html Wed Sep 12 11:23:26 2012 +0200
@@ -73,7 +73,7 @@
company: "Kellogg Associates" },
{ name: "Jeni Tennison", url: "http://www.jenitennison.com/",
company: "Independent"},
- { name: "Iván Herman", url: "http://www.w3.org/People/Ivan/",
+ { name: "Ivan Herman", url: "http://www.w3.org/People/Ivan/",
company: "W3C", companyURL: "http://www.w3.org" }
],
@@ -149,6 +149,14 @@
provide guidance for a possible future Working Group chartered to provide a Recommendation
for this transformation. As a consequence, implementers of this specification, either producers
or consumers, should note that it may change prior to any possible publication as a Recommendation.</p>
+
+<p>This Working Draft is an update of the <a href="/TR/2012/NOTE-microdata-rdf-20120308/">W3C
+Interest Group Note</a>, published in March 2012. This update adds the
+<a href="#vocab_expansion">Vocabulary Expansion</a> feature to the conversion algorithm, in response to the
+evolution of vocabularies discussed on the <a href="/2001/sw/interest/webschema.html">Web Schemas Task Force</a>
+of the <a href="/2001/sw/interest/">Semantic Web Interest Group</a> at W3C. The intention is to publish
+this draft as a new version of the Interest Group Note after gathering and incorporating community input.
+</p>
</section>
<section class="informative">
@@ -728,7 +736,7 @@
</section>
<section>
- <h2>Vocabulary Expansion</h2>
+ <h2 id="vocab_expansion">Vocabulary Expansion</h2>
<p>Microdata requires that all values of <a class="aref">itemtype</a> come from the same vocabulary. This
is required as <a class="aref">itemprop</a> values are resolved relative to that vocabulary. However,
it is often useful to define an <a>item</a> to have types from multiple different vocabularies.</p>
@@ -741,18 +749,7 @@
property IRI with the target property IRI using either
<code>http://www.w3.org/2000/01/rdf-schema#subPropertyOf</code> or
<code>http://www.w3.org/2002/07/owl#equivalentProperty</code> predicates.</p>
- <p>To allow [[RDFA-CORE]] processors to be used for microdata vocabulary expansion, microdata acts as if
- there is an implicit <code>@vocab</code> attribute set to a detected vocabulary by emitting
- a triple using the <code>rdfa:usesVocabulary</code> predicate.</p>
- <p>Vocabulary expansion MAY be performed as
- part of a larger RDF toolset including, for example,
- an <cite><a href="http://www.w3.org/TR/2009/REC-owl2-profiles-20091027/#OWL_2_RL">OWL 2 RL</a></cite> reasoner
- (see [[OWL2-PROFILES]]).
- Alternatively, expansion MAY
- also be done using a separate and dedicated (e.g., rule based) reasoner
- after the triples have been generated, or as the last
- processing step.</p>
- <p>For example, the <a>registry</a> definition for the <em>additionalType</em> property
+ <p>For example, the <a>registry</a> definition for the <em>additionalType</em> property
within schema.org, defines <em>additionalType</em> to have an <a>rdfs:subPropertyOf</a>
relationship with <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#type</code>.</p>
@@ -784,7 +781,7 @@
<> md:item (
[ a schema:Product;
- schema:additionalType <http://www.productontology.org/id/Laser_printer> .
+ schema:additionalType <http://www.productontology.org/id/Laser_printer> ;
schema:name "Laser Printer"]
);
rdfa:usesVocabulary schema: .
@@ -793,7 +790,7 @@
-->
</pre>
- <p>After performing vocabulary entailment, an additional <code>rdf:type</code> triple is generated:</p>
+ <p>After performing vocabulary expansion, an additional <code>rdf:type</code> triple is generated:</p>
<pre class="example" data-transform="updateExample">
<!--
@@ -803,7 +800,7 @@
<> md:item (
[ a schema:Product, <http://www.productontology.org/id/Laser_printer>;
- schema:additionalType <http://www.productontology.org/id/Laser_printer> .
+ schema:additionalType <http://www.productontology.org/id/Laser_printer> ;
schema:name "Laser Printer"]
)
rdfa:usesVocabulary schema: .
@@ -814,16 +811,15 @@
<section>
<h2>Vocabulary Entailment</h2>
- <p> For the purpose of vocabulary processing, microdata uses a very
- restricted subset of the OWL2 vocabulary and is based on the RDF-Based
- Semantics of OWL2 [[!OWL2-RDF-BASED-SEMANTICS]].
+ <p>Formally, and for the purpose of vocabulary processing, microdata uses a very
+ restricted subset of the OWL2 vocabulary and is based on the RDF-Based Semantics of OWL2 [[!OWL2-RDF-BASED-SEMANTICS]].
Vocabulary Entailment uses the following terms: </p>
<ul>
<li><code>rdfs:subPropertyOf</code></li>
<li><code>owl:equivalentProperty</code>
</li>
</ul>
- <p class="note">Vocabulary Entailment considers only the entailment on individuals
+ <p>Vocabulary Entailment considers only the entailment on individuals
(i.e., not on the relationships that can be deduced on the
properties or the classes themselves.)
</p>
@@ -839,30 +835,31 @@
section 4.3</a></cite>
of [[!OWL2-PROFILES]]): <code>prp-spo1</code>, <code>prp-eqp1</code>, and
<code>prp-eqp2</code>.</p>
- <p>The entailment described in this section is the <em>minimum</em>
+
+ <p>[[RDFA-CORE]] implements a more complete form of vocabulary entailement,
+ including retrieving the vocabulary URI to find additional class and property expansion definitions, as
+ described in <cite><a href="http://www.w3.org/TR/rdfa-syntax/#s_vocab_entailment">RDFa Vocabulary Entailment</a></cite>.
+ Microdata implementations MAY use RDFa Vocabulary Entailment as an alternative to implementing
+ a separate entailment algorithm. To allow [[RDFA-CORE]] processors to be used for microdata vocabulary expansion, microdata acts as if there is an implicit <code>@vocab</code> RDFa attribute set to a detected vocabulary by emitting
+ a triple using the <code>rdfa:usesVocabulary</code> predicate.</p>
+
+
+ <p class="note">The entailment described in this section is the <em>minimum</em>
useful level for microdata. Processors may, of course, choose to follow
more powerful entailment regimes, e.g., include full RDFS [[!RDF-MT]]
or OWL2 [[!OWL2-OVERVIEW]] entailments. Using those entailments
applications may perform datatype validation by checking <code>rdfs:range</code>
of a property, or use the advanced facilities offered by, e.g., OWL2’s
property chains to interlink vocabularies further.</p>
- <p class="note">[[RDFA-CORE]] implements a more complete form of vocabulary entailement,
- including retrieving the vocabulary URI to find additional class and property expansion
- definitions, as
- described in <cite><a href="http://www.w3.org/TR/rdfa-syntax/#s_vocab_entailment">RDFa Vocabulary Entailment</a></cite>.
- Microdata implementations MAY use RDFa Vocabulary Entailment as an alternative to implementing
- a separate entailment algorithm.</p>
+
</section>
<section>
<h2>Vocabulary Expansion Control of Microdata Processors</h2>
- <p>Conforming processors MUST perform vocabulary expansion.</p>
- <p>If vocabulary expansion is performed using [[RDFA-CORE]] voabulary expansion, and the
+ <p>Conforming processors MUST perform the basic vocabulary expansion.</p>
+ <p>If vocabulary expansion is performed by the microdata processor using [[RDFA-CORE]] vocabulary expansion, and the
<code>vocab_expansion</code> option is passed to the microdata processor,
- the expansion MUST be performed.</p>
- <p class="note"> Although vocabulary expansion is described in terms of
- OWL2 entailment rules, processors
- are free to use any process which obtains equivalent results.</p>
+ the full [[RDFA-CORE]] expansion MUST also be performed.</p>
</section>
</section>
@@ -1644,10 +1641,12 @@
schema:numTracks "2";
schema:tracks (
[ a schema:MusicRecording, mo:MusicalManifestation;
- schema:byArtist ("Lynard Skynard");;
+ schema:additionalType mo:MusicalManifestation;
+ schema:byArtist ("Lynard Skynard");
schema:name "Sweet Home Alabama";
schema:url <sweet-home-alabama>]
[ a schema:MusicRecording, mo:MusicalManifestation;
+ schema:additionalType mo:MusicalManifestation;
schema:byArtist ("AC/DC");;
schema:name "Shook you all Night Long";
schema:url <shook-you-all-night-long>]