--- a/model/ProvenanceModel.html Mon Nov 07 08:24:46 2011 +0000
+++ b/model/ProvenanceModel.html Mon Nov 07 09:46:10 2011 +0000
@@ -262,18 +262,18 @@
<p>When we talk about things in the world in natural language and even when we assign identifiers, we are often imprecise in ways that make it difficult to clearly and unambiguously report provenance: a resource with a URL may be understood as referring to a report available at that URL, the version of the report available there today, the report independent of where it is hosted over time, etc.</p>
-<p>Hence, to accommodate different perspectives on things and their situation in the world as perceived by us, we introduce the concept of <dfn id="concept-characterized-thing">characterized thing</dfn>, which refers to a thing and its situation in the world, as characterized by someone. A characterized thing <em>fixes some aspects</em> of a thing and its situation in the world, so that it becomes possible to express its provenance, and what causes these specific aspects to be as such. An alternative characterized thing may fix other aspects, and its provenance may be different.</p>
+<p>Hence, to accommodate different perspectives on things and their situation in the world as perceived by us, we introduce the idea of a characterized thing, which refers to a thing and its situation in the world, as characterized by someone. We then define an <dfn id="concept-entity">entity</dfn> as an identifiable characterized thing. An entity <em>fixes some aspects</em> of a thing and its situation in the world, so that it becomes possible to express its provenance, and what causes these specific aspects to be as such. An alternative entity may fix other aspects, and its provenance may be different.</p>
<div class="xmpl">
Different users may take different perspectives on a resource with
a URL. These perspectives in this conceptualization of the world are
-referred to as characterized things. Three such characterized things may be
+referred to as entities. Three such entities may be
expressed:
<ul>
<li>a report available at URL: fixes the nature of the thing, i.e. a document, and its location; </li>
<li>the version of the report available there today: fixes its version number, contents, and its date;</li>
<li>the report independent of where it is hosted and of its content over time: fixes the nature of the thing as a conceptual artifact.</li></ul>
-The provenance of these three characterized things will differ, and may be along the follow lines:
+The provenance of these three entities will differ, and may be along the follow lines:
<ul>
<li>the provenance of a report available at URL may include: the act of publishing it and making it available at a given location, possibly under some license and access control;</li>
<li>the provenance of the version of the report available there today may include: the authorship of the specific content, and reference to imported content;</li>
@@ -285,25 +285,19 @@
<div class='paolo'>can we follow through from the example. thare three perspectives, possibly by just one observer or multiple ones. but <strong>why is it so important for reporting provenance</strong> that this distinction is made? I feel we need to connect this approach to provenance recording strongly and right away</div>
-->
-<p>We do not assume that any characterization is more important than any other, and in fact, it is possible to describe the processing that occurred for the report to be commissioned, for individual versions to be created, for those versions to be published at the given URL, etc., each via a different characterized thing that characterizes the report appropriately.</p>
+<p>We do not assume that any characterization is more important than any other, and in fact, it is possible to describe the processing that occurred for the report to be commissioned, for individual versions to be created, for those versions to be published at the given URL, etc., each via a different entity that characterizes the report appropriately.</p>
<p>In the world, <dfn id="concept-activity">activities</dfn> involve
-things in multiple ways: they consume them, they process them, they
+entities in multiple ways: they consume them, they process them, they
transform them, they modify them, they change them, they relocate
them, they use them, they generate them, they are controlled by them,
etc.</p>
-<p>In our conceptualization of the world, instantaneous events, or <dfn id="concept-event">events</dfn> for short, happen in the world, which mark changes in the world, in its activities, and in its things. This specification assumes that a partial order exists between events. How practically such order is realized is beyond the scope of this specification. Possible implementations of that ordering include a single global notion of time and Lamport's style clocks.</p>
-
-<p> In this specification, the qualifier 'identifiable' is implicit whenever a reference is made to an activity or characterized thing.</p>
-
-
-<div class='note'>
-Now that "entity expression" is used to refer to the
-language construct, the term "entity" can unambiguously refer to the thing
-described by that construct; i.e. the characterized thing.
-This is raised in the following <a href="http://lists.w3.org/Archives/Public/public-prov-wg/2011Sep/0315.html">email</a>.</div>
+<p>In our conceptualization of the world, instantaneous events, or <dfn id="concept-event">events</dfn> for short, happen in the world, which mark changes in the world, in its activities, and in its entities. This specification assumes that a partial order exists between events. How practically such order is realized is beyond the scope of this specification. Possible implementations of that ordering include a single global notion of time and Lamport's style clocks.</p>
+
+<p> In this specification, the qualifier 'identifiable' is implicit whenever a reference is made to an activity or an entity.</p>
+
</section>
@@ -400,7 +394,7 @@
<p>The model includes the following elements:</p>
<ul>
- <li>An <strong>Entity Expression</strong> (noted <samp>entity</samp> in the diagram, to reflect the term used in the ASN) is a representation of a <em>characterized thing</em>. The EntityExpression may specify a set of <strong>characterizing attributes</strong>. The
+ <li>An <strong>Entity Expression</strong> (noted <samp>entity</samp> in the diagram, to reflect the term used in the ASN) is a representation of an <em>entity</em>. The EntityExpression may specify a set of <strong>attributes</strong>. The
<strong>wasComplementOf</strong> relationship is used to denote that two <samp>entities</samp> <em>complement</em> each other, in the sense that they each represent a partial, but mutually compatible characterization of the same thing.</li>
<li>A<strong>Process Execution Expression </strong>(noted <samp>processExecution</samp> in the diagram) represents an activity that has an effect on entities, namely it either <em>generates</em> or <em>uses</em> one or more entities. Use and generation are modelled by means of the <strong>used</strong> and the <strong>wasGeneratedBy</strong> relationships. Additionally, one can use the <strong>hadParticipant</strong> relation to indicate participation of an <samp>entity</samp> in a <samp>processExecution</samp>. Activities may include not only computations, but also any other type of activity that can be described in terms of their effect on <samp>entities</samp>.
@@ -525,7 +519,7 @@
<p>
-Generation Expressions (described in <a href="#expression-Generation">Section Generation</a>) represent the event at which a file is created in a specific form. To describe the modalities according to which the various characterized things are generated by a given activity, a qualifier (expression described in <a href="#expression-qualifier">Section Qualifier</a>) is introduced. The interpretation of qualifiers is application specific. Illustrations of such qualifiers for the scenario are: no qualifier is provided for <span class="name">e0</span>;
+Generation Expressions (described in <a href="#expression-Generation">Section Generation</a>) represent the event at which a file is created in a specific form. To describe the modalities according to which the various entities are generated by a given activity, a qualifier (expression described in <a href="#expression-qualifier">Section Qualifier</a>) is introduced. The interpretation of qualifiers is application specific. Illustrations of such qualifiers for the scenario are: no qualifier is provided for <span class="name">e0</span>;
<span class="name">e2</span> was generated by the editor's save function; <span class="name">e4</span> can be found on the smtp port, in the attachment section of the mail message; <span class="name">e6</span> was produced on the standard output of <span class="name">pe5</span>.</p>
<pre>
wasGeneratedBy(e0, pe0, qualifier())
@@ -542,7 +536,7 @@
<p>
Expressions of type <strong>UsedExpressions</strong> (described in <a href="#expression-Use">Section Use</a>) represent the event by which a file is read by a process execution.
-Likewise, to describe the modalities according to which the various things are used by activities, a qualifier (construct described in <a href="#expression-qualifier">Section Qualifier</a>) is introduced. Illustrations of such qualifiers are:
+Likewise, to describe the modalities according to which the various entities are used by activities, a qualifier (construct described in <a href="#expression-qualifier">Section Qualifier</a>) is introduced. Illustrations of such qualifiers are:
<span class="name">e1</span> is used in the context of <span class="name">pe1</span>'s <span class="name">load</span> functionality; <span class="name">e2</span> is used by <span class="name">pe2</span> in the context of its attach functionality; <span class="name">e3</span> is used on the standard input by <span class="name">pe5</span>. </p>
<pre>
used(pe1,e1,qualifier(fct="load"))
@@ -682,7 +676,7 @@
<h4>Entity Expression</h4>
-<p>In PROV-DM, an <dfn id="dfn-entity" title="entity">entity expression</dfn> is a representation of an identifiable characterized thing.</p>
+<p>In PROV-DM, an <dfn id="dfn-entity" title="entity">entity expression</dfn> is a representation of an entity.</p>
<p>
In PROV-ASN, an entity expression's text matches the <span class="nonterminal">entityExpression</span> production of the grammar defined in this specification document.
@@ -714,13 +708,13 @@
<p>An instance of an entity expression, noted <span class="name">entity(id, [ attr1=val1, ...])</span> in PROV-ASN:</p>
<ul>
-<li> contains an identifier <span class="name">id</span> identifying a characterized thing;</li>
-<li> contains a set of attribute-value pairs <span class="name">[ attr1=val1, ...]</span>, representing this characterized thing's situation in the world.</li>
+<li> contains an identifier <span class="name">id</span> identifying an entity;</li>
+<li> contains a set of attribute-value pairs <span class="name">[ attr1=val1, ...]</span>, representing this entity's situation in the world.</li>
</ul>
<p>
-The assertion of an instance of an entity expression, <span class="name">entity(id, [ attr1=val1, ...])</span>, states, from a given asserter's viewpoint, the existence of an identifiable characterized thing, whose situation in the world is represented by the attribute-value pairs, which remain unchanged during a characterization interval, i.e. a continuous interval between two events in the world.
+The assertion of an instance of an entity expression, <span class="name">entity(id, [ attr1=val1, ...])</span>, states, from a given asserter's viewpoint, the existence of an entity, whose situation in the world is represented by the attribute-value pairs, which remain unchanged during a characterization interval, i.e. a continuous interval between two events in the world.
</p>
@@ -730,21 +724,21 @@
<pre class="example">
entity(e0, [ type="File", location="/shared/crime.txt", creator="Alice" ])
</pre>
-states the existence of a thing of type File and location /shared/crime.txt, and creator alice, denoted by identifier e0, during some characterization interval.
+states the existence of an entity of type File and location /shared/crime.txt, and creator alice, denoted by identifier e0, during some characterization interval.
Further considerations:
<ul>
-<li>If an asserter wishes to characterize a thing with the same attribute-value pairs over several intervals, then they are required to assert multiple entity expressions, each with its own identifier (so as to allow potential dependencies between the various entity expressions to be expressed). </li>
+<li>If an asserter wishes to characterize an entity with the same attribute-value pairs over several intervals, then they are required to assert multiple entity expressions, each with its own identifier (so as to allow potential dependencies between the various entity expressions to be expressed). </li>
<li>There is no assumption that the set of attributes is complete and that the attributes are independent/orthogonal of each other.</li>
<li>A characterization interval may collapse into a single instant.</li>
<li>An entity assertion
- is about a characterized thing, whose situation in the world may be variant.
- An entity assertion is made at a particular point and is invariant, in the sense that
-its attributes are assigned a value as part of that assertion.
+ is about a thing, whose situation in the world may be variant.
+ An entity expression is asserted at a particular point and is invariant, in the sense that
+its attributes are given a value as part of that assertion.
</li>
<li>Activities are not represented by entities, but instead by process
@@ -823,7 +817,7 @@
start event precedes the end event of the represented activity.</div>
<p>A process execution expression is not an entity expression.
-Indeed, an entity expression represents a thing that exists in full at
+Indeed, an entity expression represents an entity that exists in full at
any point in its characterization interval, persists during this
interval, and preserves the characteristics that makes it
identifiable. Alternatively, an activity in something that happens,
@@ -838,7 +832,7 @@
-<p>An <dfn id="dfn-Agent">agent expression</dfn> is a representation of a characterized thing capable of
+<p>An <dfn id="dfn-Agent">agent expression</dfn> is a representation of an entity capable of
activity.</p>
<p>In PROV-ASN, an agent expression's text matches the <span class="nonterminal">agentExpression</span> production of the grammar defined in this specification document.
@@ -856,10 +850,10 @@
<p> An agent expression, written <span class="name">agent(e)</span> in PROV-ASN,
- refers to an entity expression denoted by identifier <span class="name">e</span> and representing the characterized thing capable of activity.
+ refers to an entity expression denoted by identifier <span class="name">e</span> and representing the entity capable of activity.
</p>
-<p>For a characterized thing, one can assert an agent expression or alternatively, one can infer an agent expression
+<p>For an entity, one can assert an agent expression or alternatively, one can infer an agent expression
by involvement in an activity represented by a process execution expression. </p>
@@ -931,7 +925,7 @@
</p>
<p>
-Name-value pairs occurring in annotations differ from attribute-value pairs (occurring in entity expressions and process execution expressions). Attribute-value pairs MUST be a representation of something in the world, which remain constant for the duration of the characterization interval (for entity expression) or the activity duration (for process execution expressions). It is OPTIONAL for name-value pairs to be representations of something in the world. If they are a representation of something in the world, then it MAY change value for the corresponding duration. If name-value pairs are a representation of something in the world that does not change, they are not regarded as determining characteristics of a characterized thing or activity, for the purpose of provenance. Indeed, it is not expected that provenance would contain an explanation for these attribute-values.
+Name-value pairs occurring in annotations differ from attribute-value pairs (occurring in entity expressions and process execution expressions). Attribute-value pairs MUST be a representation of something in the world, which remain constant for the duration of the characterization interval (for entity expression) or the activity duration (for process execution expressions). It is OPTIONAL for name-value pairs to be representations of something in the world. If they are a representation of something in the world, then it MAY change value for the corresponding duration. If name-value pairs are a representation of something in the world that does not change, they are not regarded as determining characteristics of an entity or activity, for the purpose of provenance.
</p>
@@ -950,8 +944,8 @@
<h4>Generation Expression</h4>
-<p>In PROV-DM, a <dfn id="dfn-Generation">generation expression</dfn> is a representation of a world event, the creation of a new characterized thing by an activity. This characterized thing did not exist before creation.
-The representation of this invent encompasses a description of the modalities of generation of this thing by this activity.</p>
+<p>In PROV-DM, a <dfn id="dfn-Generation">generation expression</dfn> is a representation of a world event, the creation of a new entity by an activity. This entity did not exist before creation.
+The representation of this event encompasses a description of the modalities of generation of this entity by this activity.</p>
<p>In PROV-ASN, a generation expression's text matches the <span class='nonterminal'>generationExpression</span> production of the grammar defined in this specification document.</p>
@@ -973,12 +967,12 @@
<p>An instance of a generation expression, written <span class="name">wasGeneratedBy(e,pe,q,t)</span> in PROV-ASN:</p>
<ul>
-<li> contains an identifier <span class="name">e</span> identifying an entity expression that represents the characterized thing that is created; </li>
-<li> contain an identifier <span class="name">pe</span> identifying a process execution expression that represents the activity that creates the characterized thing;</li>
-
-<li> contains a <a href="#expression-qualifier">generationQualifier</a> <span class="name">q</span> that describes the modalities of generation of this thing by this activity;</li>
-
-<li> MAY contain a "generation time" <span class="name">t</span>, the time at which the characterized thing was created.</li>
+<li> contains an identifier <span class="name">e</span> identifying an entity expression that represents the entity that is created; </li>
+<li> contain an identifier <span class="name">pe</span> identifying a process execution expression that represents the activity that creates the entity;</li>
+
+<li> contains a <a href="#expression-qualifier">generationQualifier</a> <span class="name">q</span> that describes the modalities of generation of this entity by this activity;</li>
+
+<li> MAY contain a "generation time" <span class="name">t</span>, the time at which the entity was created.</li>
</ul>
@@ -989,7 +983,7 @@
wasGeneratedBy(e1,pe1,qualifier(port="p1", order=1),t1)
wasGeneratedBy(e2,pe1,qualifier(port="p1", order=2),t2)
</pre>
-<p>state the existence of two events in the world (with respective times <span class="name">t1</span> and <span class="name">t2</span>), at which new characterized things, represented by entity expressions identified by <span class="name">e1</span> and <span class="name">e2</span>, are created by an activity, itself represented by a process execution expression identified by <span class="name">pe1</span>.
+<p>state the existence of two events in the world (with respective times <span class="name">t1</span> and <span class="name">t2</span>), at which new entities, represented by entity expressions identified by <span class="name">e1</span> and <span class="name">e2</span>, are created by an activity, itself represented by a process execution expression identified by <span class="name">pe1</span>.
The first one is available as the first value on port p1, whereas the other is the second value on port p1. The semantics of <span class="name">port</span> and <span class="name">order</span> in these expressions are application specific.
</p>
@@ -1017,10 +1011,11 @@
asserted.
</div>
+
The assertion of a generation event implies ordering of events in the world.
-<div class='constraint' id='generation-pe-ordering'><span class='conditional'>If</span> an assertion <span class="name">wasGeneratedBy(x,pe,q)</span> or <span class="name">wasGeneratedBy(x,pe,q,t)</span>, <span class='conditional'>then</span> generation of the thing denoted by <span class="name">x</span> precedes the end
+<div class='constraint' id='generation-pe-ordering'><span class='conditional'>If</span> an assertion <span class="name">wasGeneratedBy(x,pe,q)</span> or <span class="name">wasGeneratedBy(x,pe,q,t)</span>, <span class='conditional'>then</span> generation of the entity denoted by <span class="name">x</span> precedes the end
of <span class="name">pe</span> and follows the beginning of <span class="name">pe</span>.
</div>
@@ -1038,7 +1033,7 @@
-<p>In PROV-DM, a <dfn id="dfn-Use">use expression</dfn> is a representation of a world event: the consumption of a characterized thing by an activity. The representation includes a description of the modalities of use of this thing by this activity.</p>
+<p>In PROV-DM, a <dfn id="dfn-Use">use expression</dfn> is a representation of a world event: the consumption of an entity by an activity. The representation includes a description of the modalities of use of this entity by this activity.</p>
<p>In PROV-ASN, a use expression's text matches the <span class='nonterminal'>useExpression</span> production of the grammar defined in this specification document.</p>
@@ -1061,9 +1056,9 @@
<p>An instance of a use expression, written <span class="name">used(pe,e,q,t)</span> in PROV-ASN:</p>
<ul>
<li> refers to a process execution expression identified by <span class="name">pe</span>, which represents the consuming activity;</li>
-<li> refers to an entity expression identified by <span class="name">e</span>, which represents the characterized thing that is consumed;</li>
-<li> contains a <a href="#expression-qualifier">useQualifier</a> <span class="name">q</span>, which describes the modalities of use of this thing by this activity;</li>
-<li> MAY contain a "use time" <span class="name">t</span>, the time at which the characterized thing was used.</li>
+<li> refers to an entity expression identified by <span class="name">e</span>, which represents the entity that is consumed;</li>
+<li> contains a <a href="#expression-qualifier">useQualifier</a> <span class="name">q</span>, which describes the modalities of use of this entity by this activity;</li>
+<li> MAY contain a "use time" <span class="name">t</span>, the time at which the entity was used.</li>
</ul>
@@ -1072,7 +1067,7 @@
used(pe1,e1,qualifier(parameter="p1"),t1)
used(pe1,e2,qualifier(parameter="p2"),t2)
</pre>
-<p>state that the activity, represented by the process execution expression identified by <span class="name">pe1</span>, consumed two characterized things, represented by entity expressions identified by <span class="name">e1</span> and <span class="name">e2</span>, at times <span class="name">t1</span> and <span class="name">t2</span>, respectively; the first one was found as the value of parameter <span class="name">p1</span>, whereas the second was found as value of parameter <span class="name">p2</span>. The semantics of <span class="name">parameter</span> in these expressions is application specific.</p>
+<p>state that the activity, represented by the process execution expression identified by <span class="name">pe1</span>, consumed two entities, represented by entity expressions identified by <span class="name">e1</span> and <span class="name">e2</span>, at times <span class="name">t1</span> and <span class="name">t2</span>, respectively; the first one was found as the value of parameter <span class="name">p1</span>, whereas the second was found as value of parameter <span class="name">p2</span>. The semantics of <span class="name">parameter</span> in these expressions is application specific.</p>
<p>A reference to a given entity expression MAY appear in multiple use expressions that share
@@ -1095,8 +1090,8 @@
<div class='constraint' id='use-pe-ordering'>Given a process execution expression identified by <span class="name">pe</span>, an entity expression identified by <span class="name">e</span>, a qualifier <span class="name">q</span>, and optional time <span class="name">t</span>, <span class='conditional'>if</span>
assertion <span class="name">used(pe,e,q)</span> or <span class="name">used(pe,e,q,t)</span> holds, <span class='conditional'>then</span>
- the use of the thing represented by entity expression identified by <span class="name">e</span> precedes the end
-time contained in the process execution expression identified by <span class="name">pe</span> and follows its beginning. Furthermore, the generation of the thing denoted by entity expression identified by <span class="name">e</span> always precedes
+ the use of the entity represented by entity expression identified by <span class="name">e</span> precedes the end
+time contained in the process execution expression identified by <span class="name">pe</span> and follows its beginning. Furthermore, the generation of the entity denoted by entity expression identified by <span class="name">e</span> always precedes
its use.
</div>
@@ -1111,7 +1106,7 @@
<h3>Derivation Expression</h3>
-<p>In PROV-DM, a <dfn id="dfn-Derivation">derivation expression</dfn> is a representation that some characterized thing is transformed from, created from, or affected by another characterized thing in the world. </p>
+<p>In PROV-DM, a <dfn id="dfn-Derivation">derivation expression</dfn> is a representation that some entity is transformed from, created from, or affected by another entity in the world. </p>
<p>PROV-DM offers two different forms of derivation expressions. The first one is tightly connected to the notion of activity (represented by a process execution expression), whereas the second one is not. The first kind of assertion is particularly suitable for asserters who have an intimate knowledge of activities, is more prescriptive, but offers a more precise description of derivation, whereas the second does not put such a requirement on the asserter, and allows a less precise description of derivation to be formulated. Both expressions need to be asserted by asserters, since PROV-DM does not provide the means to infer them; however, from these assertions, further derivations can be inferred by transitive closure. </p>
@@ -1161,13 +1156,13 @@
<section id="pe-linked-derivationExpression">
<h4>Process Execution Linked Derivation Expression</h4>
-<p>A process execution linked derivation expression, which, by definition of a derivation expression, is a representation that some characterized thing is transformed from, created from, or affected by another characterized thing, also entails the existence of a process execution expression that represents an activity that transforms, creates or affects this characterized thing.</p>
+<p>A process execution linked derivation expression, which, by definition of a derivation expression, is a representation that some entity is transformed from, created from, or affected by another entity, also entails the existence of a process execution expression that represents an activity that transforms, creates or affects this entity.</p>
<p>In its full form, a process-execution linked derivation expression, written <span class="name">wasDerivedFrom(e2,e1,pe,q2,q1)</span> in PROV-ASN:</p>
<ul>
-<li> refers to an entity expression identified by <span class="name">e2</span>, which is a representation of the generated characterized thing;</li>
-<li> refers to an entity expression identified by <span class="name">e1</span>, which is a representation of the used characterized thing;</li>
-<li> refers to a process execution expression identified by <span class="name">pe</span>, which is a representation of the activity using and generating the above characterized things;</li>
+<li> refers to an entity expression identified by <span class="name">e2</span>, which is a representation of the generated entity;</li>
+<li> refers to an entity expression identified by <span class="name">e1</span>, which is a representation of the used entity;</li>
+<li> refers to a process execution expression identified by <span class="name">pe</span>, which is a representation of the activity using and generating the above entities;</li>
<li> contains a qualifier <span class="name">q2</span>, which qualifies the generation expression pertaining to <span class="name">e2</span> and <span class="name">pe</span>;</li>
<li> contains a qualifier <span class="name">q1</span>, which qualifies in the use expression pertaining to <span class="name">e1</span> and <span class="name">pe</span>.</li>
</ul>
@@ -1178,8 +1173,8 @@
<p>For convenience, PROV-DM allows for a compact, process-execution linked derivation assertion, written <span class="name">wasDerivedFrom(e2,e1)</span> in PROV-ASN, which:</p>
<ul>
-<li> refers to an entity expression identified by <span class="name">e2</span>, which is a representation of the generated characterized thing;
-<li> refers to an entity expression identified by <span class="name">e1</span>, which is a represenation of the used characterized thing.
+<li> refers to an entity expression identified by <span class="name">e2</span>, which is a representation of the generated entity;
+<li> refers to an entity expression identified by <span class="name">e1</span>, which is a represenation of the used entity.
</ul>
@@ -1192,14 +1187,14 @@
<p>
state the existence of process-linked derivations;
the first expresses that the activity represented by the process execution <span class="name">pe4</span>, by
-using the thing represented by <span class="name">e3</span> obtained on the <span class="name">in</span> channel
+using the entity denoted by <span class="name">e3</span> obtained on the <span class="name">in</span> channel
derived the
-thing represented by entity <span class="name">e5</span> and generated it on
+entity denoted by <span class="name">e5</span> and generated it on
channel <span class="name">out</span>. The second is similar for <span class="name">e3</span> and <span class="name">e2</span>, but it leaves the process execution expression and associated qualifiers implicit. The meaning of "channel" is application specific.
</p>
-<p>If a derivation expression holds for <span class="name">e2</span> and <span class="name">e1</span>, then it means that the thing represented by the entity expression identified by <span class="name">e1</span> has an influence on the thing represented by the entity expression identified by <span class="name">e2</span>, which is captured by a dependency between their attribute values; it also implies temporal ordering. These are specified as follows:</p>
+<p>If a derivation expression holds for <span class="name">e2</span> and <span class="name">e1</span>, then it means that the entity represented by the entity expression identified by <span class="name">e1</span> has an influence on the entity represented by the entity expression identified by <span class="name">e2</span>, which is captured by a dependency between their attribute values; it also implies temporal ordering. These are specified as follows:</p>
<div class='constraint' id='derivation-attributes'>Given a process execution expression denoted by <span class="name">pe</span>, entity expressions denoted by <span class="name">e1</span> and <span class="name">e2</span>, qualifiers <span class="name">q1</span> and <span class="name">q2</span>, the assertion <span class="name">wasDerivedFrom(e2,e1,pe,q2,q1)</span>
or <span class="name">wasDerivedFrom(e2,e1)</span> holds <span class='conditional'>if and only if</span>
@@ -1211,8 +1206,8 @@
<div class='constraint' id='derivation-use-generation-ordering'>Given a process execution expression identified by <span class="name">pe</span>, entity expressions identified by <span class="name">e1</span> and <span class="name">e2</span>, qualifiers <span class="name">q1</span> and <span class="name">q2</span>, <span class='conditional'>if</span> the assertion <span class="name">wasDerivedFrom(e2,e1,pe,q2,q1)</span>
or <span class="name">wasDerivedFrom(e2,e1)</span> holds, <span class='conditional'>then</span>
the use
-of characterized thing denoted by <span class="name">e1</span> precedes the generation of
-the characterized thing denoted by <span class="name">e2</span>.
+of entity denoted by <span class="name">e1</span> precedes the generation of
+the entity denoted by <span class="name">e2</span>.
</div>
@@ -1261,7 +1256,7 @@
<span class='conditional'>if</span> <span class="name">wasDerivedFrom(e2,e1)</span> and <span class="name">wasGeneratedBy(e2,pe,q2)</span> hold, <span class='conditional'>then</span> there exists a qualifier <span class="name">q1</span>,
such that <span class="name">used(pe,e1,q1)</span> also holds.
</div>
-<p>This inference is justified by the fact that the characterized thing represented by entity expression identified by <span class="name">e2</span> is generated by at most one activity in a given account (see <a href="#generation-unicity">generation-unicity</a>). Hence, this process execution expression is also the one referred to in the use expression of <span class="name">e1</span>.
+<p>This inference is justified by the fact that the entity represented by entity expression identified by <span class="name">e2</span> is generated by at most one activity in a given account (see <a href="#generation-unicity">generation-unicity</a>). Hence, this process execution expression is also the one referred to in the use expression of <span class="name">e1</span>.
</p>
@@ -1285,20 +1280,20 @@
<p>A process-execution independent derivation expression, written <span class="name">wasEventuallyDerivedFrom (e2, e1)</span> in PROV-ASN,
<ul>
-<li> contains an identifier <span class="name">e2</span>, denoting an entity expression, which represents the generated characterized thing;
-<li> contains an identifier <span class="name">e1</span>, denoting an entity expression, which represents the used characterized thing.
+<li> contains an identifier <span class="name">e2</span>, denoting an entity expression, which represents the generated entity;
+<li> contains an identifier <span class="name">e1</span>, denoting an entity expression, which represents the used entity.
</ul>
<p>If a derivation expression (wasEventuallyDerivedFrom) holds for <span class="name">e2</span> and <span class="name">e1</span>, then
-this means that the thing represented by entity expression identified by <span class="name">e1</span> has an influence on the thing represented entity expression identified by <span class="name">e2</span>,
+this means that the entity represented by entity expression identified by <span class="name">e1</span> has an influence on the entity represented entity expression identified by <span class="name">e2</span>,
which at the minimum implies temporal ordering, specified as follows:</p>
<div class='constraint' id='derivation-generation-generation-ordering'>
Given two entity expressions denoted by <span class="name">e1</span> and <span class="name">e2</span>, <span class='conditional'>if</span> the expression <span class="name">wasEventuallyDerivedFrom(e2,e1)</span>
holds, <span class='conditional'>then</span> the
-generation event of the characterized thing represented by the entity expression denoted by <span class="name">e1</span> precedes the generation event of
-the characterized thing represented by the entity expression denoted by <span class="name">e2</span>.
+generation event of the entity represented by the entity expression denoted by <span class="name">e1</span> precedes the generation event of
+the entity represented by the entity expression denoted by <span class="name">e2</span>.
</div>
<p>Note that temporal ordering is between generations of <span class="name">e1</span>
@@ -1341,8 +1336,8 @@
An instance of a transitive derivation expression, written <span class="name">dependedOn(e2, e1)</span> in PROV-ASN:
<ul>
-<li> contains an identifier <span class="name">e2</span>, denoting an entity expression, which represents the characterized thing that is the result of the derivation;
-<li> contains an identifier <span class="name">e1</span>, denoting an entity expression, which represents the characterized thing that the derivation relies upon.
+<li> contains an identifier <span class="name">e2</span>, denoting an entity expression, which represents the entity that is the result of the derivation;
+<li> contains an identifier <span class="name">e1</span>, denoting an entity expression, which represents the entity that the derivation relies upon.
</ul>
<p>The expression <span class="name">dependedOn</span> can only be inferred; in other words, it cannot be asserted. It is
transitive by definition and relies on the previously defined derivation assertions for its
@@ -1387,7 +1382,7 @@
<section id="expression-Control">
<h3>Control Expression</h3>
-<p> A <dfn id="dfn-Control">control expression</dfn> is a representation of the involvement of characterized thing (represented as an agent expression or an entity expression) in an activity, which is represented by a process execution expression; a control qualifier qualifies this involvement.</p>
+<p> A <dfn id="dfn-Control">control expression</dfn> is a representation of the involvement of entity (represented as an agent expression or an entity expression) in an activity, which is represented by a process execution expression; a control qualifier qualifies this involvement.</p>
<p>In PROV-ASN, a control expression's text matches the <span class="nonterminal">controlExpression</span> production of the grammar defined in this specification document.
</p>
@@ -1407,8 +1402,8 @@
<p>An instance of a control expression, written <span class="name">wasControlledBy(pe,ag,q)</span> in PROV-ASN:</p>
<ul>
<li> contains an identifier <span class="name">pe</span> denoting a process execution expression, representing the controlled activity;
-<li> refers to an agent expression or an entity expression identified by <span class="name">ag</span>, representing the controlling characterized thing;
-<li> contains a qualifier <span class="name">q</span>, qualifying the involvement of the thing in the activity.
+<li> refers to an agent expression or an entity expression identified by <span class="name">ag</span>, representing the controlling entity;
+<li> contains a qualifier <span class="name">q</span>, qualifying the involvement of the entity in the activity.
</ul>
@@ -1417,7 +1412,7 @@
<pre class="example">
wasControlledBy(pe3,a4,qualifier[role="author"])
</pre>
-<p>states that the activity, represented by the process execution expression denoted by <span class="name">pe3</span> saw the involvement of a characterized thing, represented by entity expression denoted by <span class="name">a4</span> in the capacity of author. This specification reserves the qualifier name <span class="name">role</span> (see Section <a href="#expression-qualifier">Qualifier</a>) to denote the function of a characterized thing with respect to an activity.
+<p>states that the activity, represented by the process execution expression denoted by <span class="name">pe3</span> saw the involvement of an entity, represented by entity expression denoted by <span class="name">a4</span> in the capacity of author. This specification reserves the qualifier name <span class="name">role</span> (see Section <a href="#expression-qualifier">Qualifier</a>) to denote the function of an entity with respect to an activity.
</p>
</section>
@@ -1428,16 +1423,16 @@
<h3>Complementarity Expression</h3>
-<p>A <dfn id="complementOf">complementarity expression</dfn> is a relationship between two characterized things stated to have compatible characterization over some continuous interval between two events.</p>
+<p>A <dfn id="complementOf">complementarity expression</dfn> is a relationship between two entities stated to have compatible characterization over some continuous interval between two events.</p>
<p>
-The rationale for introducing this relationship is that in general, at any given time, for a thing in the world, there may be multiple ways of characterizing it, and hence multiple representations can be asserted by different asserters. In the example that follows, suppose thing "Royal Society" is represented by two asserters, each using a different set of attributes. If the asserters agree that both representations refer to "The Royal Society", the question of whether any correspondence can be established between the two representations arises naturally. This is particularly relevant when (a) the sets of attributes used by the two representations overlap partially, or (b) when one set is subsumed by the other. In both these cases, we have a situation where each of the two asserters has a partial view of "The Royal Society", and establishing a correspondence between them on the shared attributes is beneficial, as in case (a) each of the two representation <em>complements</em> the other, and in case (b) one of the two (that with the additional attributes) complements the other.</p>
-
-<p>This intuition is made more precise by considering the entities that form the representations of characterized things at a certain point in time.
+The rationale for introducing this relationship is that in general, at any given time, for an entity in the world, there may be multiple ways of characterizing it, and hence multiple representations can be asserted by different asserters. In the example that follows, suppose thing "Royal Society" is represented by two asserters, each using a different set of attributes. If the asserters agree that both representations refer to "The Royal Society", the question of whether any correspondence can be established between the two representations arises naturally. This is particularly relevant when (a) the sets of attributes used by the two representations overlap partially, or (b) when one set is subsumed by the other. In both these cases, we have a situation where each of the two asserters has a partial view of "The Royal Society", and establishing a correspondence between them on the shared attributes is beneficial, as in case (a) each of the two representation <em>complements</em> the other, and in case (b) one of the two (that with the additional attributes) complements the other.</p>
+
+<p>This intuition is made more precise by considering the entities that form the representations of entities at a certain point in time.
An entity expression represents, by means of attribute-value pairs, a thing and its situation in the world, which remain constant over a characterization interval.
-As soon as the thing's situation changes, this marks the end of the characterization interval for the entity expression representing it. The thing's novel situation is represented by an attribute with a new value, or an entirely different set of attribute-value pairs, embodied in another entity expression, with a new characterization interval. Thus, if we overlap the timelines (or, more generally, the sequences of value-changing events) for the two characterized things, we can hope to establish correspondences amongst the entity expressions that represent them at various points along that events line. The figure below illustrates this intuition.</p>
+As soon as the thing's situation changes, this marks the end of the characterization interval for the entity expression representing it. The thing's novel situation is represented by an attribute with a new value, or an entirely different set of attribute-value pairs, embodied in another entity expression, with a new characterization interval. Thus, if we overlap the timelines (or, more generally, the sequences of value-changing events) for the two entities, we can hope to establish correspondences amongst the entity expressions that represent them at various points along that events line. The figure below illustrates this intuition.</p>
<img src="complement-of.png" alt="illustration complementOf"/>
@@ -1446,7 +1441,7 @@
<p>The term <em>compatible</em> used above means that a mapping can be established amongst the values of attributes in P and found in the two entity expession. This generalizes to the case where attribute sets P1 and P2 of A, and B, respectively, are not identical but they can be mapped to one another. The simplest case is the identity mapping, in which A and B share attribute set P, and furthermore the values assigned to attributes in P match exactly.</p>
-<p>It is important to note that the relation holds only for the characterization intervals of the entity expessions involved As soon as one attribute changes value in one of them, new correspondences need to be found amongst the new entities. Thus, the relation has a validity span that can be expressed in terms of the event lines of the thing.</p>
+<p>It is important to note that the relation holds only for the characterization intervals of the entity expessions involved As soon as one attribute changes value in one of them, new correspondences need to be found amongst the new entities. Thus, the relation has a validity span that can be expressed in terms of the event lines of the entity.</p>
<!--
The "IVP of" relationship is designed to represent pairs of entities that correspond to each other. By their own nature, an entity remains valid only as long as all of its attributes do not change their value. It follows that the correspondence "B IVP of A" is only valid within the time interval during which such invariance attribute holds for both A and B. When any of the attribute values change in either A or B, those entities are replaced by new ones, and a new correspondence may be established. Thus, "IVP of" is defined relative to the intersection of the temporal intervals for which A and B are valid.
@@ -1531,7 +1526,7 @@
<div class="note">Proposal to change the name to "Dependencies amongst Process Executions" to avoid ambiguities</div>
<p>PROV-DM allows two forms of temporal relationships between activities to be expressed.
-An <dfn id="InformationFlowOrdering">information flow ordering expression</dfn> is a representation that a characterized thing was generated by an activity, before it was used by another activity.
+An <dfn id="InformationFlowOrdering">information flow ordering expression</dfn> is a representation that an entity was generated by an activity, before it was used by another activity.
A <dfn id="ControlOrdering">control ordering expression</dfn> is a representation that the end of
an activity precedes the start of another activity.
</p>
@@ -1642,7 +1637,7 @@
<section id="expression-Revision">
<h3>Revision Expression</h3>
-<p> A <dfn id="dfn-Revision">revision expression</dfn> is a representation of the creation of a characterized thing considered to be a variant of another. Deciding whether something is made available as a revision of something else usually involves an agent who represents someone in the world who takes responsibility for declaring that the former is variant of the latter. </p>
+<p> A <dfn id="dfn-Revision">revision expression</dfn> is a representation of the creation of an entity considered to be a variant of another. Deciding whether something is made available as a revision of something else usually involves an agent who represents someone in the world who takes responsibility for declaring that the former is variant of the latter. </p>
<p>In PROV-ASN, a revision expression's text matches the <span class="nonterminal">revisionExpression</span> production of the grammar defined in this specification document.
</p>
@@ -1663,13 +1658,13 @@
<p>An instance of a revision expression, written <span class="name">wasRevisionOf(e2,e1,ag)</span> in PROV-ASN:</p>
<ul>
-<li> contains an identifier <span class="name">e2</span> identifying an entity that represents a newer version of a thing;
-<li> contains an identifier <span class="name">e1</span> identifying an entity that represents an older version of a thing;
+<li> contains an identifier <span class="name">e2</span> identifying an entity that represents a newer version of an entity;
+<li> contains an identifier <span class="name">e1</span> identifying an entity that represents an older version of an entity;
<li> MAY refer to a responsible agent with identifier <span class="name">ag</span>.
</ul>
-<p>A revision expression can only be asserted, since it needs to include a reference to an agent who represents someone in the real world who bears responsibility for declaring a variant of a thing. However, it needs to satisfy the following constraint, linking the two entity expressions by a derivation, and stating them to be a complement of a third entity expression.</p>
+<p>A revision expression can only be asserted, since it needs to include a reference to an agent who represents someone in the real world who bears responsibility for declaring a variant of an entity. However, it needs to satisfy the following constraint, linking the two entity expressions by a derivation, and stating them to be a complement of a third entity expression.</p>
<div class='constraint' id='wasRevision'>
Given two identifiers <span class="name">old</span> and <span class="name">new</span> identifying two entities, and an identifier <span class="name">ag</span> identifying an agent,
@@ -1706,7 +1701,7 @@
<section id="expression-Participation">
<h3>Participation Expression</h3>
-<p>A <dfn id="dfn-Participation">participation expression</dfn> is a representation of the involvement of a characterized thing in an activity. A participation expression can be asserted or inferred.</p>
+<p>A <dfn id="dfn-Participation">participation expression</dfn> is a representation of the involvement of an entity in an activity. A participation expression can be asserted or inferred.</p>
<p>In PROV-ASN, a participation expression's text matches the <span class="nonterminal">participationExpression</span> production of the grammar defined in this specification document.</p>
@@ -1729,10 +1724,10 @@
<ul>
<li> contains to identifier <span class="name">pe</span> identifying a process execution expression representing an activity;
<li> contains an identifier <span class="name">e</span> identifying an entity expression, which is
-a representation of a characterized thing involved in this activity.
+a representation of an entity involved in this activity.
</ul>
-<p>A thing's participation in an activity can be by direct use or direct control. But also, if a thing and situation are characterized in two complementary manners (and are represented by two entity expressions related by <span class="name">isComplementOf</span>), if one of them participates in an activity, so does the other. The following captures the definition of participation.</p>
+<p>An entity's participation in an activity can be by direct use or direct control. But also, if an entity and situation are characterized in two complementary manners (and are represented by two entity expressions related by <span class="name">isComplementOf</span>), if one of them participates in an activity, so does the other. The following captures the definition of participation.</p>
<div class='constraint' id='participation'>
Given two identifiers <span class="name">pe</span> and <span class="name">e</span>, respectively identifying a process execution expression and an entity expression, the expression <span class="name">hadParticipant(pe,e)</span> holds <span class='conditional'>if and only if</span>:
@@ -1928,7 +1923,7 @@
wasGeneratedBy(e0,pe1,qualifier(fct="create"))
... )
</pre>
-<p>with identifier <span class="name">acc2</span>, containing assertions by asserter by <span class="name">http://example.org/asserter2</span> stating that thing represented by entity expression identified by <span class="name">e0</span> was generated by an activity represented by process execution expression identified by <span class="name">pe1</span> instead of <span class="name">pe0</span> in the previous account <span class="name">acc0</span>. If accounts <span class="name">acc0</span> and <span class="name">acc2</span> are merged together, the resulting set of expressions violates <a href="#generation-unicity">generation-unicity</a>.</p>
+<p>with identifier <span class="name">acc2</span>, containing assertions by asserter by <span class="name">http://example.org/asserter2</span> stating that the entity represented by entity expression identified by <span class="name">e0</span> was generated by an activity represented by process execution expression identified by <span class="name">pe1</span> instead of <span class="name">pe0</span> in the previous account <span class="name">acc0</span>. If accounts <span class="name">acc0</span> and <span class="name">acc2</span> are merged together, the resulting set of expressions violates <a href="#generation-unicity">generation-unicity</a>.</p>
<p>Account expressions constitue a scope for identifiers. Since accounts can be nested, their scope can also be nested; thus, the scope of identifiers should be understood in the context of such nested scopes. When an expression with an identifier occurs directly within an account, then its identifier denotes this expression in the scope of this account, except in sub-accounts where expressions with the same identifier occur. </p>
@@ -2072,7 +2067,7 @@
</ul>
-<p>The PROV data model introduces the qualifier <span class="name">role</span> in the <a href="#prov-dm-namespace">PROV-DM namespace</a> to denote the function of a characterized thing with respect to an activity, in the context of a use/generation/control relation. The value associated with a <span class="name">role</span> attribute MUST be conformant with <span class="nonterminal">Literal</span>. </p>
+<p>The PROV data model introduces the qualifier <span class="name">role</span> in the <a href="#prov-dm-namespace">PROV-DM namespace</a> to denote the function of an entity with respect to an activity, in the context of a use/generation/control relation. The value associated with a <span class="name">role</span> attribute MUST be conformant with <span class="nonterminal">Literal</span>. </p>
<p>
@@ -2165,8 +2160,8 @@
<h4>Temporal Events</h4>
Four kinds of discrete events underpin the PROV-DM data model. They are:
<ol>
-<li>Generation of a characterized thing by an activity: identifies the final instant of a characterized thing's creation timespan, after which it becomes available for use.</li>
-<li>Use of a characterized thing by an activity: identifies the first instant of a characterized thing's consumption timespan.</li>
+<li>Generation of an entity by an activity: identifies the final instant of an entity's creation timespan, after which it becomes available for use.</li>
+<li>Use of an entity by an activity: identifies the first instant of an entity's consumption timespan.</li>
<li>Start of an activity: identifies the instant an activity, represented by a process execution, starts;</li>
<li>End of an activity: identifies the instant an activity, represented by a process execution, ends.</li>
</ol>
@@ -2261,7 +2256,7 @@
<p>The PROV data model provides several extensibility points that allow designers to specialize it to specific applications or domains. We summarize these extensibility points here:
<ul>
-<li> Attributes are constructs of the data model that allow representations of aspects of the world's things and activities to be expressed. Applications are free to introduce application-specific attributes, according to their perspective on the world. Attributes for a given application can be distinguished by qualifying them with a prefix denoting a namespace declared in a namespace declaration.
+<li> Attributes are constructs of the data model that allow representations of aspects of the world's entities and activities to be expressed. Applications are free to introduce application-specific attributes, according to their perspective on the world. Attributes for a given application can be distinguished by qualifying them with a prefix denoting a namespace declared in a namespace declaration.
<p>The <a href="#prov-dm-namespace">PROV-DM namespace</a> declares a set of reserved attributes: <span class="name">type</span>, <span class="name">location</span>.</li>
@@ -2281,7 +2276,7 @@
<li>Domain specific values can be expressed by means of typed literals. </li>
</ul>
-<p>The PROV data model is designed to be application and technology independent, but specializations of PROV-DM are welcome and encouraged. To ensure inter-operability, specializations of the PROV data model that exploit the extensibility points summarized in this section MUST preserve the semantics specified in this document. For instance, a qualified attribute on a domain specific entity expression MUST represent an aspect of a characterized thing and this aspect MUST remain unchanged during the characterization's interval of this entity expression.</p>
+<p>The PROV data model is designed to be application and technology independent, but specializations of PROV-DM are welcome and encouraged. To ensure inter-operability, specializations of the PROV data model that exploit the extensibility points summarized in this section MUST preserve the semantics specified in this document. For instance, a qualified attribute on a domain specific entity expression MUST represent an aspect of an entity and this aspect MUST remain unchanged during the characterization's interval of this entity expression.</p>
@@ -2410,7 +2405,7 @@
<section>
<h3>Attribution Expression</h3>
-<p>An attribution expression represents that a characterized thing is ascribed to an agent and is compliant with the <span class="nonterminal">attributionExpression</span> production.</p>
+<p>An attribution expression represents that an entity is ascribed to an agent and is compliant with the <span class="nonterminal">attributionExpression</span> production.</p>
<div class='grammar'>
<span class="nonterminal">attributionExpression</span> :=
@@ -2450,7 +2445,7 @@
-<p> A quotation expression is a representation of the repeating or copying of some part of a characterized thing, compatible with
+<p> A quotation expression is a representation of the repeating or copying of some part of an entity, compatible with
the <span class="nonterminal">quotationExpression</span> production.</p>
<div class='grammar'>
@@ -2493,7 +2488,7 @@
<section>
<h3>Summary Expression</h3>
-<p>A summary expression represents that a characterized thing is a synopsis or abbreviation of another entity. A summary expression is compliant with the
+<p>A summary expression represents that an entity is a synopsis or abbreviation of another entity. A summary expression is compliant with the
<span class="nonterminal">summaryExpression</span> production.</p>
<div class='grammar'>
@@ -2523,8 +2518,8 @@
<section>
<h3>Original Source Expression</h3>
-<p>An original-source expression represents a characterized thing in
-which another characterized thing first appeared. A original-source
+<p>An original-source expression represents an entity in
+which another entity first appeared. A original-source
expression is compliant with the
<span class="nonterminal">originalSourceExpression</span> production.</p>
@@ -2540,8 +2535,8 @@
<p> An assertion hadOriginalSource, written <span class="name"> hadOriginalSource(e2,e1)</span>:</p>
<ul>
-<li>contains an identifier <span class="name">e1</span> identifying the entity expression representing the original thing;
-<li>contains an identifier <span class="name">e2</span> identifying an entity expression, representing a thing that had appeared previously.
+<li>contains an identifier <span class="name">e1</span> identifying the entity expression representing the original entity;
+<li>contains an identifier <span class="name">e2</span> identifying an entity expression, representing an entity that had appeared previously.
</ul>
<p>
@@ -2556,16 +2551,16 @@
<section id="resource-section">
<h2>Resources, URIs, Entities, Identifiers, and Scope</h2>
-<p>This specification introduces the notion of an identifiable characterized thing in the world. In PROV-DM, an entity expression is a representation of such an identifiable characterized thing. An entity expression includes an identifier identifying this characterized thing. Identifiers are URIs (TBC). </p>
+<p>This specification introduces the notion of an identifiable entity in the world. In PROV-DM, an entity expression is a representation of such an identifiable entity. An entity expression includes an identifier identifying this entity. Identifiers are URIs (TBC). </p>
<p>The term 'resource' is used in a general sense
for whatever might be identified by a URI [[!RFC3986]]. On the Web, a URI denotes a resource, without any expectation that the resource is accessed. </p>
-<p>The purpose of this section is to clarify the relationship between resource and the notions of characterized thing and entity expression. </p>
-
-<p>A resource is an instance of a thing in the world. One may take multiple perspectives on such a thing and its situation in the world, fixing some its aspects.</p>
-
-<p> We refer to the example of section <a href="#conceptualization">2.1</a> for a resource (at some URL) and three different perspectives, referred to as characterized things. Three different entity expressions can be expressed for this report, which in the PROV-ASN sample below, are expressed within a same account.
+<p>The purpose of this section is to clarify the relationship between resource and the notions of entity and entity expression. </p>
+
+<p>A resource is an instance of an entity in the world. One may take multiple perspectives on such a thing and its situation in the world, fixing some its aspects.</p>
+
+<p> We refer to the example of section <a href="#conceptualization">2.1</a> for a resource (at some URL) and three different perspectives, referred to as entities. Three different entity expressions can be expressed for this report, which in the PROV-ASN sample below, are expressed within a same account.
</p>
<pre>
@@ -2578,10 +2573,10 @@
...)
</pre>
-<p>Each entity expression contains an idenfier that identifies the characterized thing it represents.
+<p>Each entity expression contains an idenfier that identifies the entity it represents.
In this example, three identifiers were minted using the URN syntax with "example" namespace.</p>
-<p>Given that the report is a resource denoted by the URI <span class="name">http://example.org/crime.txt</span>, we could simply use this URI as the identifier of an entity. This would avoid us minting new URIs. Hence, the report URI would play a double role: as a URI it denotes a resource accessible at that URI, and as a PROV-DM identifier, it identifies a specific characterization of this report. A given identifier identifies a single characterized thing within the scope of an account. Hence, below, all entities expressions have been given the same identifier but appear in the scope of different accounts. </p>
+<p>Given that the report is a resource denoted by the URI <span class="name">http://example.org/crime.txt</span>, we could simply use this URI as the identifier of an entity. This would avoid us minting new URIs. Hence, the report URI would play a double role: as a URI it denotes a resource accessible at that URI, and as a PROV-DM identifier, it identifies a specific characterization of this report. A given identifier identifies a single entity within the scope of an account. Hence, below, all entities expressions have been given the same identifier but appear in the scope of different accounts. </p>
<pre>
account(acc2,
@@ -2649,6 +2644,13 @@
-->
+<section class="appendix">
+ <h2>Changes Since Previous Version</h2>
+<ul>
+<li>11/07/11: Defined entity as identifiable characterized thing, and updated text accordingly.</li>
+<li>10/08/11: Made explicit the term expression wherever was appropriate, including section titles.</li>
+</ul>
+ </section>
<section class="appendix">
<h2>Acknowledgements</h2>