--- a/rdf-concepts/index.html Mon Jul 18 09:37:44 2011 -0700
+++ b/rdf-concepts/index.html Wed Jul 20 13:56:53 2011 +0100
@@ -128,7 +128,7 @@
<p>RDF Concepts and Abstract Syntax defines an abstract syntax
on which RDF is based, and which serves to link its concrete
syntax to its formal semantics. It also includes discussion of
- design goals, key concepts, datatyping, character normalization
+ key concepts, datatyping, character normalization
and handling of IRIs.</p>
</section>
@@ -146,11 +146,12 @@
<p>The Resource Description Framework (RDF) is a framework for
representing information in the Web.</p>
- <p>This document defines an abstract syntax on which RDF is based,
+ <p>This document defines an abstract syntax (a data model)
+ on which RDF is based,
and which serves to link its concrete syntax to its formal
semantics.
This abstract syntax is quite distinct from XML's tree-based infoset
- [[XML-INFOSET]]. It also includes discussion of design goals,
+ [[XML-INFOSET]]. It also includes discussion of
key concepts, datatyping, character normalization
and handling of IRIs.</p>
@@ -185,142 +186,6 @@
<section id="conformance"></section>
-<section id="section-Overview" class="informative">
- <h2>Motivations and Goals</h2>
-
- <p class="issue">Does this section add value?</p>
-
- <p>RDF has an abstract syntax that reflects a simple graph-based
- data model, and formal semantics with a rigorously defined notion
- of entailment providing a basis for well founded deductions in RDF
- data.</p>
-
-<section id="section-motivation">
- <h3>Motivation</h3>
-
- <p>The development of RDF has been motivated by the following uses,
- among others:</p>
-
- <ul>
- <li>Web metadata: providing information about Web resources and
- the systems that use them (e.g. content rating, capability
- descriptions, privacy preferences, etc.)</li>
-
- <li>Applications that require open rather than constrained
- information models (e.g. scheduling activities, describing
- organizational processes, annotation of Web resources, etc.)</li>
-
- <li>To do for machine processable information (application data)
- what the World Wide Web has done for hypertext: to allow data to
- be processed outside the particular environment in which it was
- created, in a fashion that can work at Internet scale.</li>
-
- <li>Interworking among applications: combining data from several
- applications to arrive at new information.</li>
-
- <li>Automated processing of Web information by software agents:
- the Web is moving from having just human-readable information to
- being a world-wide network of cooperating processes. RDF provides
- a world-wide lingua franca for these processes.</li>
- </ul>
-
- <p>RDF is designed to represent information in a minimally
- constraining, flexible way. It can be used in isolated
- applications, where individually designed formats
- might be more direct and easily understood, but RDF's generality offers greater value from
- sharing. The value of information thus increases as it becomes
- accessible to more applications across the entire Internet.</p>
-</section>
-
-
-<section>
- <h3 id="section-design-goals">Design Goals</h3>
-
- <p>The design of RDF is intended to meet the following goals:</p>
-
- <ul>
- <li>having a simple data model</li>
- <li>having formal semantics and provable inference</li>
- <li>using an extensible IRI-based vocabulary</li>
- <li>using an XML-based syntax</li>
- <li>supporting use of XML schema datatypes</li>
- <li>allowing anyone to make statements about any
- resource</li>
- </ul>
-
-
-<section id="section-simple-data-model">
- <h4>A Simple Data Model</h4>
-
- <p>RDF has a simple data model that is easy for applications to
- process and manipulate. The data model is independent of any
- specific serialization syntax.</p>
-
- <p class="note">The term “model” used here in “data model” has a
- completely different sense to its use in the term “model theory”.
- See [[!RDF-MT]]
- for more information about “model theory” as used in the literature of mathematics and logic.</p>
-</section>
-
-
-<section id="section-formal-semantics">
- <h4>Formal Semantics and Inference</h4>
-
- <p>RDF has a formal semantics which provides a dependable basis for
- reasoning about the meaning of an RDF expression. In particular, it
- supports rigorously defined notions of entailment which provide a
- basis for defining reliable rules of inference in RDF data.</p>
-</section>
-
-
-<section id="section-extensible-vocab">
- <h4>Extensible IRI-based Vocabulary</h4>
-
- <p>The vocabulary is fully extensible, being based on IRIs.
- IRIs are used for naming all kinds of things in RDF.</p>
-
- <p>The other kind of value that appears in RDF data is a
- literal.</p>
-</section>
-
-
-<section id="section-xml-serialization">
- <h4>XML-based Syntax</h4>
-
- <p>RDF has a recommended XML serialization form [[!RDF-SYNTAX-GRAMMAR]], which can be used to encode the
- data model for exchange of information among applications.</p>
-</section>
-
-
-<section id="section-use-xsd">
- <h4>Use XML Schema Datatypes</h4>
-
- <p>RDF can use values represented according to XML schema datatypes
- [[!XMLSCHEMA-2]], thus assisting the
- exchange of information between RDF and other XML applications.</p>
-</section>
-
-
-<section id="section-anyone">
- <h4>Anyone Can Make Statements About Any Resource</h4>
-
- <p>To facilitate operation at Internet scale, RDF is an
- open-world framework that allows anyone to make statements
- about any resource.</p>
- <p>In general, it is not assumed that complete information
- about any resource is available. RDF does not prevent anyone
- from making assertions that are nonsensical or inconsistent
- with other statements, or the world as people see it. Designers
- of applications that use RDF should be aware of this and may
- design their applications to tolerate incomplete or
- inconsistent sources of information.</p>
-</section>
-
-</section>
-
-</section>
-
-
<section id="section-Concepts" class="informative">
<h2>RDF Concepts</h2>
@@ -569,76 +434,6 @@
</section>
-<section id="section-SimpleFacts">
- <h3>RDF Expression of Simple Facts</h3>
-
- <p>Some simple facts indicate a relationship between
- two things.
-Such a fact may be represented as an RDF triple in which the predicate
-names the relationship, and the subject and object denote the two things.
-
-
- A familiar representation of such a fact might be
- as a row in a table in a relational database. The table has
- two columns, corresponding to the subject and the object of the
- RDF triple.
- The name of the table corresponds to the predicate
- of the RDF triple. A further familiar representation may be as a
- two place predicate
- in first order logic.</p>
-
- <p>
-Relational databases permit a table to have an arbitrary number of columns,
-a row of which expresses information corresponding to a predicate in first
-order logic with an arbitrary number of places. Such a row, or predicate,
-has to be decomposed for representation as RDF triples. A simple form of
-decomposition introduces a new blank node, corresponding to the row, and a
-new triple is introduced for each cell in the row. The subject of each
-triple is the new blank node, the predicate corresponds to the column name,
-and object corresponds to the value in the cell. The new blank node may
-also have an <code>rdf:type</code> property whose value corresponds
-to the table name.
-</p>
-
- <p>As an example, consider Figure 6 from the [[RDF-PRIMER]]:
-
-</p>
-
- <div class="figure">
- <img src="fig6may19" alt="Using a Blank Node" /><br />
- RDF Primer Figure 6: Using a Blank Node
- </div>
-
-
- <p>
-This information might correspond to a row in a table <code>"STAFFADDRESSES"</code>,
- with a primary key
-<code>STAFFID</code>,
- and additional columns
-<code>STREET</code>,
-<code>STATE</code>,
-<code>CITY</code> and
-<code>POSTALCODE</code>.
- </p>
-
- <p>
-Thus, a more complex fact is expressed in RDF using a
-conjunction (logical-AND) of simple binary relationships. RDF does not
-provide means to express negation (NOT) or disjunction (OR). </p>
-
- <p>Through its use of extensible IRI-based vocabularies, RDF
- provides for expression of facts about arbitrary subjects; i.e.
- assertions of named properties about specific named things. An IRI
- can be constructed for any thing that can be named, so RDF facts
- can be about any such things. <!--
- And, as noted above, RDF also
- provides for expression of assertions about unnamed things, which
- may be fully identifiable in terms of such assertions [[TAP-RBD]].
- -->
- </p>
-</section>
-
-
<section id="section-Entailment">
<h3>Entailment</h3>
@@ -1535,6 +1330,7 @@
<h2>Changes from RDF 2004</h2>
<ul>
+ <li>2011-07-20: Removed informative sections “Motivations and Goals” (see <a href="http://www.w3.org/TR/rdf-concepts/#section-Overview">RDF 2004 version</a>) and “RDF Expression of Simple Facts” (see <a href="http://www.w3.org/TR/rdf-concepts/#section-SimpleFacts">RDF 2004 version</a>)</li>
<li>2011-06-01: Replaced the URI References section with <a href="#section-IRIs">new section on IRIs</a>, and changed “RDF URI Reference” to “IRI” throughout the document, except in <a href="#section-fragID">section 8</a>.</li>
<li>2011-06-01: Changed language tag definition to require well-formedness according to BCP47; added a note that this invalidates some RDF</li>
<li>2011-05-25: Added boxes for known WG issues throught the document</li>