--- a/rdf-primer/index.html	Tue Aug 13 14:17:04 2013 +0100
+++ b/rdf-primer/index.html	Tue Aug 13 15:16:29 2013 +0100
@@ -259,7 +259,8 @@
       in RFC 3987 [[!RFC3987]]. They can be used to identify both documents
       (e.g. a Web page) and things (e.g. a person). </p>
 
-      <p>For example, the IRI for the "La Joconde" painting in <a href="http://www.europeana.eu/">Europeana</a> is:</p>
+      <p>For example, the IRI for the "La Joconde" painting in the <a href="http://www.europeana.eu/">Europeana</a> 
+      digital library is:</p>
 
       <pre>http://data.europeana.eu/item/08501/BFEDA8C5F46930228355F50FA9F5298D982DD6B8</pre>
 
@@ -296,15 +297,37 @@
 
       <h3>Graphs</h3>
 
-      <p></p>
-
-    </section>
+      <p>RDF provides a mechanism to group RDF statements in <i>graphs</i> and associate them
+      with an IRI. For example the statements in the example above could be grouped in two graphs. A first
+      graph could be provided by a social networking site 
+      and identified by <code>http://example.com/bob</code>:</p>
 
-    <section id="subsection-datasets">
+      <pre>
+        &lt;Bob&gt; &lt;is a friend of&gt; &lt;Alice&gt;.
+        &lt;Bob&gt; &lt;is born on&gt; &lt;the 4th of July 1990&gt;.
+        &lt;Bob&gt; &lt;likes&gt; &lt;La Joconde&gt;.
+      </pre>
 
-      <h3>Datasets</h3>
+      <p>A second graph could be provided by <a href="http://www.europeana.eu/">Europeana</a>
+      and identified by <code>http://data.europeana.eu/data/item/08501/BFEDA8C5F46930228355F50FA9F5298D982DD6B8</code>:</p>
 
-      <!-- needed? -->
+      <pre>
+        &lt;Leonardo da Vinci&gt; &lt;is the creator of&gt; &lt;La Joconde&gt;.
+        &lt;La Joconde&gt; &lt;is on display in&gt; &lt;the Louvre&gt;.
+      </pre>
+
+      <p>We can then make statements about these two graphs, for example adding license and provenance
+      information.</p>
+
+      <pre>
+        &lt;http://example.com/bob&gt; &lt;is published by&gt; &lt;http://example.org&gt;.
+        &lt;http://example.com/bob&gt; &lt;has license&gt; &lt;http://creativecommons.org/licenses/by/3.0/&gt;.
+      </pre>
+
+      <p class="issue">We should introduce default graphs here as well.</p>
+
+      <p>These two graphs constitute an RDF <i>dataset</i>. RDF datasets are collections of 
+      RDF graphs.</p>
 
     </section>