--- a/primer/Primer.html Tue Mar 20 09:51:59 2012 +0000
+++ b/primer/Primer.html Tue Mar 20 15:22:54 2012 +0000
@@ -161,7 +161,6 @@
<ul>
<li>An intuitive explanation of how PROV-DM models provenance.</li>
<li>Worked examples that can be followed to produce your own PROV-DM data.</li>
- <li>Answers to frequently asked questions regarding how the model should be applied.</li>
</ul>
<p>
@@ -279,7 +278,7 @@
<h3>Activities</h3>
<p>
- Activities are how entities come into
+ <i>Activities</i> are how entities come into
existence and how their attributes change to become new entities,
often making use of previously existing entities to achieve this.
For example, if the second version of document D was generated
@@ -294,7 +293,6 @@
<section>
<h3>Use and Generation</h3>
-
<p>
Activities <i>generate</i> new entities.
For example, writing a document brings the document into existence, while
@@ -312,11 +310,10 @@
</section>
<section>
- <h3>Agents</h3>
-
+ <h3>Agents and Responsibility</h3>
<p>
- An agent is a type of entity that takes an active role in an activity such
- that it can be assigned some degree of responsibility for the activity taking
+ An <i>agent</i> is a type of entity that takes an active role in an activity such
+ that it can be assigned some degree of <i>responsibility</i> for the activity taking
place. An agent can be a person, a piece of software, an inanimate object, an organization, or
other entities that may be ascribed responsibility.
Several agents can be associated with an activity.
@@ -325,21 +322,27 @@
provenance of a that chart, we could state that the person who created the
chart was an agent involved in its creation, and that the software used to
create the chart was also an agent involved in that activity.
- An agent may be acting on behalf of others, e.g. an employee on behalf of their
+ An agent may be <i>acting on behalf</i> of others, e.g. an employee on behalf of their
organization, and we can express such chains of responsibility in the provenance.
</p>
<p>
+ We can also assert that an entity is <i>attributed</i> to an agent to express
+ the agent's responsibility for that entity, possibly along with other agents.
+ This assertion can be understood as a shorthand
+ for saying that the agent was responsible for the activity which generated
+ the entity.
+ </p>
+ <!-- p>
Since agents are a kind of entity, it is therefore possible to
associate provenance records with the agents themselves.
In the running example, we
can also represent the provenance of the software used to create the chart, and specify the agents involved in
producing that software, such as the vendor.
- </p>
+ </p -->
</section>
<section>
<h3>Roles</h3>
-
<p>
A <i>role</i> is a description of the function or the part that an entity
played in an activity. Roles specify
@@ -356,8 +359,14 @@
</section>
<section>
- <h3>Revisions and Derivation</h3>
-
+ <h3>Derivation and Revision</h3>
+ <p>
+ When one entity's existence, content, characteristics and so on are
+ at least partly due to another entity, then we say that the former is
+ <i>derived</i> from the latter. For example, one document may contain
+ material copied from another,
+ and a chart is derived from the data that is used to create it.
+ </p>
<p>
A given entity, such as a document, may go through multiple <i>revisions</i>
(also called versions and other comparable terms) over time. Between revisions,
@@ -366,16 +375,57 @@
and PROV-DM allows one to relate those entities by making an assertion that
one is a revision of another.
</p>
+ </section>
+
+ <section>
+ <h3>Plans</h3>
<p>
- When one entity's existence, content, characteristics and so on are
- at least partly due to another entity, then we say that the former is
- <i>derived</i> from the latter. For example, one document may contain
- material copied from another,
- and a chart is derived from the data that is used to create it.
+ Activities may follow pre-defined procedures, such as recipes, tutorials, instructions, or workflows.
+ PROV-DM refers to these, in general, as <i>plans</i>, and allows the assertion that a plan was followed, by agents,
+ in executing an activity.
</p>
</section>
+ <section>
+ <h3>Time</h3>
+ <p>
+ Time is critical information in many provenance records.
+ PROV-DM allows the timing of significant events to be asserted, including
+ when an entity was generated or used, or when an activity started
+ and finished. For example, the model can be used to assert facts such as when a new
+ version of a document was created (generation time), when a document was
+ edited (start and end of the editing activity).
+ </p>
+ </section>
+ <section>
+ <h3>Alternate Entities and Specialization</h3>
+ <p>
+ Entities are defined in a flexible way in PROV-DM, allowing for different
+ perspectives to be taken as appropriate for the application. For example,
+ some PROV-DM assertions may refer to a document D, other assertions may be
+ more specifically about the second version of D, while another set may
+ concern the copy of D stored on a particular hard disk. All three are
+ different entities referred to with different identifiers, but are also perspectives
+ or abstractions on the same thing. Because of
+ this, the entities are said to be <i>alternates</i> of each other, and
+ asserted as such. Being aware that two entities are alternates allows those
+ consuming the PROV-DM data to know that understanding the provenance of one entity is salient
+ to understanding the provenance of the other.
+ </p>
+ <p>
+ In some cases, we can be more informative still. Where one entity is a more
+ general or longer term perspective on the same thing as another, we can say that the latter
+ is a <i>specialization</i> of the former. For example, both the second version
+ of document D and the copy of D on the hard disk are specializations of document D in
+ general. That is, D's period of existence will contain the periods in which the
+ second version existed, and where a copy of D was on the hard disk. It is helpful
+ to assert specialization in provenance data, because it indicates that everything
+ which was true of one entity (the more specialized) was at some point true of
+ the other (the more general).
+ </p>
+ </section>
+
</section>
<section>
@@ -583,7 +633,7 @@
</section>
<section>
- <h3>Revision and Derivation</h3>
+ <h3>Derivation and Revision</h3>
<p>
After looking at the detail of the compilation activity, there appears
@@ -610,10 +660,6 @@
</section>
</section>
- <section>
- <h2>Frequently asked questions</h2>
- </section>
-
<section class="appendix">
<h2>Abstract Syntax Notation for Examples</h2>
<p>
@@ -692,7 +738,7 @@
</section>
<section>
- <h3>Revision and Derivation</h3>
+ <h3>Derivation and Revision</h3>
<pre class="example asn">
wasRevisionOf(ex:dataSet2, ex:dataSet1).
</pre>
@@ -722,6 +768,12 @@
<li>Updated wasControlledBy to wasAssociatedWith.</li>
<li>Changed (Qualified)Involvement classes and associated relations to match current ontology.</li>
<li>Added actedOnBehalfOf in intuition and example.</li>
+ <li>Made derivation more prominent than revision.</li>
+ <li>Removed the FAQ section.</li>
+ <li>Added intuition section on plans.</li>
+ <li>Added intuition section on time.</li>
+ <li>Added intuition section on alternates and specialization.</li>
+ <li>Included description of attribution in intuition section on agents and responsibility.</li>
</ul>
</section>