--- a/requirements/latest/index.html Wed Aug 03 11:03:35 2011 -0700
+++ b/requirements/latest/index.html Wed Aug 03 13:26:08 2011 -0700
@@ -16,6 +16,7 @@
var preProc = {
apply: function(c) {
// extend the bibliography entries
+ berjon.biblio["LINKED-DATA"] = "<cite><a href=\"http://www.w3.org/DesignIssues/LinkedData\">Linked Data</a></cite>, T. Berners-Lee. World Wide Web Consortium, 18 June 2009. W3C Note. URL: http://www.w3.org/DesignIssues/LinkedData.";
// process the document before anything else is done
var refs = document.querySelectorAll('adef') ;
@@ -130,7 +131,7 @@
p.replaceChild(sp, item) ;
}
}
- } ;
+ };
var respecConfig = {
@@ -146,9 +147,9 @@
// if there is a previously published draft, uncomment this and set its YYYY-MM-DD date
// and its maturity status
- previousPublishDate: "2011-07-03",
+ previousPublishDate: "2011-07-13",
previousMaturity: "ED",
- previousDiffURI: "http://json-ld.org/requirements/ED/20110703/index.html",
+ previousDiffURI: "http://json-ld.org/requirements/ED/20110713/index.html",
diffTool: "http://www.aptest.com/standards/htmldiff/htmldiff.pl",
// if there a publicly available Editor's Draft, this is the link
@@ -233,18 +234,42 @@
is a simple way to express objects in a syntax compatible with JavaScript.
</dd>
<dt>Linked Data</dt><dd>
- According to <cite><a
- href="http://en.wikipedia.org/wiki/Linked_Data">Wikipedia</a></cite>, Linked Data ...
- <blockquote cite="http://en.wikipedia.org/wiki/Linked_Data">
- describes a method of publishing structured data so that it can be interlinked and
- become more useful. It builds upon standard Web technologies such as HTTP and URIs,
- but rather than using them to serve web pages for human readers, it extends them to
- share information in a way that can be read automatically by computers. This
- enables data from different sources to be connected and queried.
- </blockquote>
+ Linked Data is a term used to describe data relationships through interconnected documents. The
+ basic tenets are described in the [[LINKED-DATA]] design note by Tim Berners-Lee:
+ <ol cite="http://www.w3.org/DesignIssues/LinkedData">
+ <li>
+ <p>
+ Use <small>URI</small>s as names for things
+ </p>
+ </li>
+ <li>
+ <p>
+ Use <small>HTTP</small> <small>URI</small>s so that
+ people can look up those names.
+ </p>
+ </li>
+ <li>
+ <p>
+ When someone looks up a <small>URI</small>, provide
+ useful information, using the standards (RDF*, SPARQL).
+ </p>
+ </li>
+ <li>
+ <p>
+ Include links to other <small>URIs</small>. so that they
+ can discover more things.
+ </p>
+ </li>
+ </ol>
+ </dd>
+ <dt>Structured Data</dt><dd>
+ Structured Data describes general means of describing inter-relationships between entities in a way that can be
+ described using a graph or tree structure. JSON is an example of a grammar for describing Structured Data. In
+ the context of JSON-LD, Structured Data refers to JSON objects in which the subject may not have a IRI, or
+ where the IRI is not dereferencable, or does not retrieve a representation of the object to which it refers.
</dd>
<dt><tdef>JSON Object</tdef></dt><dd>
- From [[RFC4627]]: <blockquote>
+ From [[RFC4627]]: <blockquote cite="http://www.ietf.org/rfc/rfc4627.txt">
An object structure is represented as a pair of curly brackets surrounding zero or
more name/value pairs (or members). A name is a string. A single colon comes after
each name, separating the name from the value. A single comma separates a value
@@ -268,13 +293,7 @@
<li><tdef>Linked Data</tdef> is a set of documents, each containing a representation of a linked data graph.</li>
<li>A <tdef>linked data graph</tdef> is a labeled directed graph, where nodes are <tref>subject</tref>s or <tref>object</tref>s, and edges are properties.</li>
<li>A <tdef>subject</tdef> is any node in a <tref>linked data graph</tref> with at least one outgoing edge.</li>
- <li>
- A <tref>subject</tref> MAY be labeled with a IRI.
- <p class="issue">
- There is some controversy over the use of MAY vs. SHOULD. Could a subject be labeled with a literal?
- Can nodes be unlabeled (i.e., like RDF Blank Nodes)?
- </p>
- </li>
+ <li>A <tref>subject</tref> SHOULD be labeled with a IRI.</li>
<li>A <tdef>property</tdef> is an edge of the <tref>linked data graph</tref>.</li>
<li>A <tref>property</tref> SHOULD be labeled with an IRI.</li>
<li>An <tdef>object</tdef> is a node in a <tref>linked data graph</tref> with at least one incoming edge.</li>
@@ -283,20 +302,33 @@
<li>A <tdef>literal</tdef> is an <tref>object</tref> with a label that is not an IRI</li>
</ol>
</section>
+ <section><h2>Structured Data</h2>
+ <p>
+ Definitions for Linked Data are often stricter than is required for many applications, where it is not feasible
+ or desirable to identify every object with an IRI which resolves to a <tref>Linked Data</tref> representation
+ of the IRI used to reference it. In such cases, graphs may be described with unlabeled nodes, or nodes having
+ non-dereferencable IRIs.
+ </p>
+ <p>
+ <tdef>Structured Data</tdef> is described as a super-set of <tref>Linked Data</tref> in which <tref>subject</tref> or <tref>object</tref> nodes are not labeled with a dereferencable IRI. The concept of
+ a <tref>linked data graph</tref> is extended to include nodes in which nodes are not labeled with dereferencable IRIs.
+ </p>
+ </section>
<section><h2>JSON-LD</h2>
- <p>The following are taken to be requirements for creating <tref>Linked Data</tref> using JSON.</p>
- <p class="issue">
- This section has not been discussed on a teleconference
- </p>
+ <p>The following are taken to be requirements for creating <tref>Linked Data</tref> in JSON.</p>
<ol>
<li>A JSON-LD document MUST be able to express a <tref>linked data graph</tref>.</li>
<li>
A JSON-LD document uses <trefs>JSON object</trefs>s, arrays, numbers, strings and
other literal names to express semantic information.
</li>
+ <li>
+ <trefs>JSON object</trefs>s, arrays, numbers, strings and literal names MUST resolve to nodes in
+ a <tref>linked data graph</tref>..
+ </li>
<li>A <tref>subject</tref> is represented with a <tref>JSON object</tref>.</li>
<li>There MUST be a way label a <tref>JSON object</tref> with an IRI.</li>
- <li>There MUST be a way to reference an un-labeled JSON object that does not have a direct child relationship.</li>
+ <li>There MAY be a way to reference an un-labeled JSON object that does not have a direct child relationship.</li>
<li>JSON name/value pairs are used to describe property-object relationships.</li>
<li>There MUST be a way to associate a IRI with the name in a JSON name/value pair.</li>
<li>JSON strings MAY represent literals.</li>
@@ -306,6 +338,7 @@
<li>JSON booleans, numbers and other literal values represent specific datatyped literals.</li>
<li>A JSON array MAY be used to associate multiple <tref>object</tref>s with a <tref>subject</tref> through a common <tref>property</tref>.</li>
<li>A JSON array MUST NOT be used to imply an order to the component entities.</li>
+ <li>A JSON-LD document SHOULD be able to express ordered object relationships.</li>
</ol>
</section>
</section>