--- a/rdf-primer/index.html	Wed Nov 27 12:34:55 2013 +0100
+++ b/rdf-primer/index.html	Wed Nov 27 15:00:07 2013 +0100
@@ -250,10 +250,10 @@
    <pre>
       &lt;subject&gt;  &lt;predicate&gt; &lt;object&gt;
     </pre>
-    <p>The <strong>subject</strong> is the resource we like to
+    <p>The <strong>subject</strong> represents the resource we like to
     make a statement about. The <strong>predicate</strong> represents
-    the feature we want to make a statement about. The
-    <strong>object</strong> represents the value of the feature
+    a property of the subject. The
+    <strong>object</strong> represents the value of the property 
     for this subject. Because RDF statements consist of three elements they are called
     <strong>triples</strong>.</p>
 
@@ -459,29 +459,30 @@
     <h2>RDF Vocabularies</h2>
 
     <p>The RDF data model provides a way to make statements about
-    (Web) resources. As we mentioned, this data model does not make any
-    assumptions about what these resources stand for. In practice, RDF
+    resources. As we mentioned, this data model does not make any
+    assumptions about what resource IRIs stand for. In practice, RDF
     is typically used in combination with vocabularies or other
     conventions that provide semantic information about these
     resources. </p>
 
-    <p>To support the definition of vocabularies RDF provides a
-    vocabulary description language called RDF-Schema
+    <p>To support the definition of vocabularies RDF provides
+    the RDF-Schema language
     [[!RDF-SCHEMA]]. This language allows one to define semantic
     characteristics of
     RDF data. For example, one can state that the IRI 
-    <code>ex:friendOf</code> can be used as a predicate and that the subject and
-    object of this property must be resources of class
+    <code>ex:friendOf</code> can be used as a property and that the
+    domain and
+    range of this property must be resources of class
     </code>ex:Person</code>. <p>
 
     <p>RDF Schema uses the notion of "class" to
-    model groups of resources that can act as subject or object. The
+    specify categories that can be used to classifiy resources. The
     term "property" is used to model predicates.  The main modeling
     constructs in RDF Schema are listed in the table below:
 
-    <p class="issue">The statement about classes is not completely
-    true. But otherwise the story about classes becomes very
-    complicated.</p>
+    <p class="issue">
+    TPDO: rephrase/extend the above based on Pat's comments
+    </p>
 
 <table id="table-rdf-schema">
   <tbody>
@@ -547,15 +548,15 @@
   &lt;is a good friend of&gt; &lt;subPropertyOf&gt; &lt;is a friend of&gt;
   </pre>
 
-<p>One of first RDF Schemas used worldwide was the
+<p>One of first RDF vocabularies used worldwide was the
 <a href="http://www.foaf-project.org/">"Friend of a Friend"</a> (FOAF)
-schema for describing social networks. Other typical examples of RDF
+vocabulary for describing social networks. Other typical examples of RDF
 vocabularies are:</p>
 
 <dl>
   <dt><a href="http://dublincore.org/documents/dcmi-terms/">Dublic Core</a></dt>
   <dd>The Dublic Core Metadata Initiative maintains a metadata element
-  set for describing a wide range of resources. The scheme provides
+  set for describing a wide range of resources. The vocabulary provides
   properties such as "creator", "publisher" and "title".</dd>
 
   <dt><a href="http://schema.org/">schema.org</a>
@@ -576,7 +577,7 @@
   Data Cloud</a>.</dd>
 
   <dt><a href="http://www.w3.org/2004/02/skos/">SKOS</a></dt>
-  <dd>SKOS is an RDF vocabulary for publishing classification schemes
+  <dd>SKOS is a meta-vocabulary for publishing classification schemes
   such as terminologies and thesauri on the Web. SKOS is since 2009 a W3C
   recommendation and is widely used in the library world. Library of
   Congress published its Subject Headings as a <a
@@ -584,10 +585,10 @@
   vocabulary</a>.</dd> 
 </dl>
 
-<p>RDF Schema provides basic facilities for modeling semantics of RDF
-data. For a specification of these semantics the reader is referred to
-the RDF Semantics document [[RDF11-MT]]. For more comprehensive
-semantic modeling of RDF data the W3C recommends using the Web Ontology
+<p>For a formal specification of the semantics of the RDF Schema
+constructs the reader is referred to
+the RDF Semantics document [[RDF11-MT]]. Users interested in more comprehensive
+semantic modeling of RDF data might consider using the Web Ontology
 Language OWL [[OWL2-OVERVIEW]]. </p>
 
 </section>
@@ -596,7 +597,11 @@
 
     <h2>Writing RDF graphs</h2>
 
-    <p>Many different concrete syntaxes exist for RDF. In the next two
+    <p>Many different concrete syntaxes exist for writing down RDF
+    graphs. However, different encodings of the smae graph lead
+    to exactly the same triples. </p>
+
+    <p>In the next two
     subsections we show RDF syntax examples using the Turtle and Trig
     language, because these two languages are best suited for human
     consumption. The final subsection lists the other RDF syntaxes,
@@ -607,6 +612,14 @@
     corresponding samples for the Turtle and TriG examples in this
     section. </p>
 
+    <p class="issue">
+    TODO: Add graph diagram to stress abstract graph syntax.
+    </p>
+
+   <p class="issue">
+    TODO: Add example with a bnode, here or in Appenxix.
+    </p>
+
     <section id="subsection-turtle">
 
       <h3>Turtle</h3>
@@ -793,8 +806,7 @@
       <dd>JSON-LD [[JSON-LD]] (<a href="#subsection-jsonld">example</a>) 
       provides a JSON syntax for RDF graphs and datasets.
       JSON-LD can be used to transform JSON documents to RDF with
-      minimal changes, therefore bringing the benefits of RDF to the
-      JSON world. These benefits include universal identifiers for
+      minimal changes. JSON-LD offers universal identifiers for
       JSON objects, a mechanism in which a JSON document can refer to 
       an object described in another JSON document elsewhere on the
       Web, as well as datatype and language handling. JSON-LD