--- a/model/working-copy/towards-wd4.html Mon Feb 13 12:16:09 2012 +0000
+++ b/model/working-copy/towards-wd4.html Mon Feb 13 12:17:02 2012 +0000
@@ -63,6 +63,12 @@
"2011, Working Draft. "+
"URL: <a href=\"http://www.w3.org/TR/prov-dm-constraints/\">http://www.w3.org/TR/prov-dm-constraints/</a>",
+ "PROV-ASN":
+ "Luc Moreau and Paolo Missier (eds.) ... "+
+ "<a href=\"http://www.w3.org/TR/prov-asn/\"><cite>PROV-ASN ....</cite></a>. "+
+ "2011, Working Draft. "+
+ "URL: <a href=\"http://www.w3.org/TR/prov-asn/\">http://www.w3.org/TR/prov-asn/</a>",
+
"PROV-AQ":
"Graham Klyne and Paul Groth (eds.) Luc Moreau, Olaf Hartig, Yogesh Simmhan, James Meyers, Timothy Lebo, Khalid Belhajjame, and Simon Miles "+
"<a href=\"http://www.w3.org/TR/prov-aq/\"><cite>Provenance Access and Query</cite></a>. "+
@@ -214,13 +220,13 @@
<p>A set of specifications, referred to as the PROV family of specifications, define the various aspects
that are necessary to achieve this vision in an inter-operable
-way, the first of which is this document:</p>
+way:</p>
<ul>
<li>A data model for provenance, which is presented in three documents:
<ul>
<li> PROV-DM (part I): the provenance data model itself, expressed in natural language (this document);
-<li> PROV-DM-CONSTRAINTS (part II): constraints underpinning the data model (REF TO ADD);
-<li> PROV-ASN (part III): a notation to express instances of that data model for human consumption (REF TO ADD);
+<li> PROV-DM-CONSTRAINTS (part II): constraints underpinning the data model [[PROV-DM-CONSTRAINTS]];
+<li> PROV-ASN (part III): a notation to express instances of that data model for human consumption [[PROV-ASN]];
</ul>
</li>
@@ -238,7 +244,7 @@
<p>This specification intentionally presents the key concepts of the PROV Data Model, without drilling down into all its subtleties. Using these key concepts, it becomes possible to write useful provenance assertions very quickly, and publish or embed them along side the data they relate to. </p>
-<p>However, it becomes challenging for provenance, like for any other form of metadata, when the data it is about changes. To address this challenge, an <em>upgrade path</em> is proposed to enrich simple provenance, with extra-descriptions that help qualify the subject of provenance and provenance itself, with attributes and interval, intended to satisfy a comprehensive set of constraints. These aspects are covered in the companion specification (PROV-DM part II, Ref to ADD).
+<p>However, it becomes challenging for provenance, like for any other form of metadata, when the data it is about changes. To address this challenge, an <em>upgrade path</em> is proposed to enrich simple provenance, with extra-descriptions that help qualify the subject of provenance and provenance itself, with attributes and interval, intended to satisfy a comprehensive set of constraints. These aspects are covered in the companion specification [[PROV-DM-CONSTRAINTS]].
</p>
@@ -251,13 +257,14 @@
applied to a short scenario, encoded in PROV-ASN, and illustrated
graphically.</p>
-<p><a href="#data-model-concepts">Section 4</a> provides the normative definition of PROV-DM.</p>
+<p><a href="#data-model-concepts">Section 4</a> provides the definition of PROV-DM.</p>
<p><a href="#common-relations">Section 5</a> introduces further relations offered by PROV-DM, including relations for data collections and domain-independent common relations.</p>
<p><a href="#extensibility-section">Section 6</a> summarizes PROV-DM extensibility points.</p>
-<p><a href="#FurtherConsiderations">Section 7</a> discusses further considerations of the PROV data model.</p>
+<p><a href="#FurtherConsiderations">Section 7</a> introduces constraints that can be applied to the PROV data model
+and that are covered in [[PROV-DM-CONSTRAINTS]].</p>
</section>
@@ -295,14 +302,16 @@
<section id='conceptualization'>
<h1>Overview</h1>
-PROV-DM is a data model for describing the provenance of <em>Entities</em>, that is, of things in the world. The term "Things" encompasses a broad diversity of concepts, including digital objects such as a file or web page, physical things such as a building or a printed book, or a car as well as abstract concepts and ideas. One can regard any Web resource as an example of Entity in this context. This section provides an overview of the main elements of the PROV data model.
+This section provides an overview of the main elements and relations of the PROV data model.
+
<section id='section-entity-activity-agent'>
<h2>Entity, Activity, Agent</h2>
-
+<p>PROV-DM is a data model for describing the provenance of <em>Entities</em>, that is, of things in the world. The term "Things" encompasses a broad diversity of concepts, including digital objects such as a file or web page,
+physical things such as a building or a printed book, or a car as well as abstract concepts and ideas. One can regard any Web resource as an example of Entity in this context. </p>
<p><dfn title="concept-entity">Entities</dfn> are things in the world one
wants to provide provenance for. For the purpose of this
@@ -311,22 +320,27 @@
</p>
-<!--
<div class="anexample" id="entity-example">
-An entity may be a web page at a URI, a file in a file system, a car or an idea.
+<p>An entity may be the document at URI <a href="http://www.w3.org/TR/prov-dm/">http://www.w3.org/TR/prov-dm/</a>, a file in a file system, a car or an idea.</p>
</div>
--->
-
-<p>An <dfn title="concept-activity">Activity</dfn> is anything that can operate on entities. In particular, activities may produce, consume, or transform an entity. Activities that operate on digital entities may for example move, copy, or duplicate them.
+
+
+
+<p>An <dfn id="concept-activity">activity</dfn> is anything that involves
+entities; this involvement can take multiple forms: consuming them, processing them,
+transforming them, modifying them, changing them, relocating
+them, using them, generating them, being associated with them,
+etc. Activities that operate on digital entities may for example move, copy, or duplicate them.</p>
<div class="anexample" id="activity-example">
-An activity may be the publishing of a document on the web, sending a tweet, extracting metadata embedded in a file, or driving a car from Boston to Cambridge, assembling a data set based on a set of measurements, performing a statistical analysis over a data set, sorting news items according to some criteria, running a sparql query over a triple store, and editing a file.
+<p>An activity may be the publishing of a document on the web, sending a twitter message, extracting metadata embedded in a file, or driving a car from Boston to Cambridge, assembling a data set based on a set of measurements, performing a statistical analysis over a data set, sorting news items according to some criteria, running a sparql query over a triple store, and editing a file.</p>
</div>
-<p>An <dfn title="concept-agent">agent</dfn> is a type of entity that can be associated to an activity, to indicate that it bears some form of responsibility for the activity taking
-place.
+
+<p>An <dfn id="concept-agent">agent</dfn> 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.</p>
+
<p>The key purpose of agents is to assign responsibility
for activities.
@@ -365,7 +379,7 @@
publication of a new version of a document.</p>
-<p>Usage examples include a procedure beginning to consume a parameter, a service starting to read a value on a port, a program beginning to read a configuration
+<p>Usage examples include a procedure beginning to consume an argument, a service starting to read a value on a port, a program beginning to read a configuration
file, or the point at which an ingredient, such as eggs, is being added in a baking activity. Usage may entirely consume an entity (e.g. eggs are no longer available after being added to
the mix); alternatively, a same entity may be used multiple times, possibly by different activities (e.g. a file on a file system can be read indefinitely).</p>
@@ -374,8 +388,8 @@
<p>Activities are consumers of entities and producers of entities. In some case, the consumption of entity influences the creation of another in some way. This notion is captured by derivations, defined as follows.</p>
-<p><dfn title="concept-derivation">Derivation</dfn> is the fact that some entity is transformed from, created from, or affected by another entity in the world. </p>
-<!-- doesn't seem right to say fact, should I use influence? -->
+<p><dfn title="concept-derivation">Derivation</dfn> is something by which some entity is transformed from, created from, or affected by another entity in the world. </p>
+
<div class="anexample" id="derivation-example">
<p>Examples of derivation include the transformation of a relational table into a
@@ -398,7 +412,7 @@
<div class="anexample" id="plan-example">
<p>
-A plan can be a blog post tutorial for how to set up a web server, a list of instructions for a micro-processor execution, a cook's written recipe for chocolate cake, or a workflow for a scientific experiment.
+A plan can be a blog post tutorial for how to set up a web server, a list of instructions for a micro-processor execution, a cook's written recipe for a chocolate cake, or a workflow for a scientific experiment.
</p>
</div>
@@ -417,8 +431,8 @@
<p>
Having found a resource, a user may want to retrieve its
provenance. For users to decide whether they can place their trust in
-that resource, they may to analyse its provenance, but also determine
-who this provenance is attributed to, and when it was
+that resource, they may want to analyse its provenance, but also determine
+who the provenance is attributed to, and when it was
generated. Hence, from the PROV-DM data model, the provenance is
regarded as an entity, an AccountEntity, for which provenance can be
sought.
@@ -426,7 +440,7 @@
</div>
-<p>Three types of agents are recognized by PROV-DM because they are commonly encountered in application making data and documents available on the Web: persons, software agents, and organizations.</p>
+<p>Three types of agents are recognized by PROV-DM because they are commonly encountered in applications making data and documents available on the Web: persons, software agents, and organizations.</p>
<div class="anexample" id="software-agents-example">
<p> Even software agents can be assigned some responsibility for the effects they have in the world, so for example if one is using a Text Editor and one's laptop crashes, then one would say
@@ -459,22 +473,28 @@
cases, those activities reflect the execution of a plan that was
designed in advance to guide the execution. PROV-DM allows attaching
a plan to an activity, which represents what was intended to
-happen. The plan can be useful for various tasks, for example to
+happen. Representing the plan explicitly in the provenance can be useful for various tasks: for example, to
validate the execution as represented in the provenance record, to
manage expectation failures, or to provide explanations.</p>
-<p>An <dfn title="concept-activityAssociation">activity association</dfn> is a relation between an activity and an agent, indicating that the agent had an active role in the activity. It further allow an activity to be associated with a plan, which a set of
-actions or steps intended by the agent to achieve some goals in the context of this activity.</p>
+<p>An <dfn title="concept-activityAssociation">activity association</dfn> is an assignment of responsibility to an agent for an activity, indicating that the agent had an active role in the activity. It further allows for a plan to be specified, which is the plan
+intended by the agent to achieve some goals in the context of this activity.</p>
<div class="anexample" id="association-example">
-<p>Examples of association between an activity and agent include designing, participation, initiation and termination, timetabling or sponsoring. </p>
+<p>Examples of association between an activity and agent are:
+<ul>
+<li>creation of a web page under the guidance of a designer;</li>
+<li>various forms of participation in a panel discussion, including audience member, panelist, or panel chair;</li>
+<li>a public event, sponsored by a company, and hosted by a museum;</li>
+<li>an XSLT transform initiated by a user;</li>
+</ul>
</div>
-<p>An <dfn title="concept-responsibilityChain">responsibility chain</dfn> is a relation between two agents,
-indicating that a "subordinate" agent acted on behalf of a "responsible" agent, in the context of an activity.</p>
+<p>A <dfn title="concept-responsibilityChain">responsibility chain</dfn> is a relation between two agents,
+indicating that a "subordinate" agent acted on behalf of a "responsible" agent, in the context of an activity. The nature of this relation is intended to be broad, and includes delegation, contractual relation</p>
@@ -571,7 +591,7 @@
</pre>
</li>
-<li>The activity was associated with the Consortium agent, and proceeded according to the publication policy
+<li>The activity was associated with the Consortium agent, and proceeded according to its publication policy
<pre>
wasAssociatedWith(ex:pub2, w3:Consortium @ pr:rec-advance)
</pre>
@@ -585,7 +605,7 @@
<p>The graphical illustration takes the form of a graph. Entities, activities and agents are represented as nodes, with oval, rectangular, and octogonal shapes, respectively. Usage,
Generation, Derivation, and Activity Association are represented as directed edges.</p>
-<p>Entities are layed out according to the ordering of their generation event. We endeavor to show time progressing from top to bottom This means that edges for Usage, Generation and
+<p>Entities are layed out according to the ordering of their generation event. We endeavor to show time progressing from top to bottom. This means that edges for Usage, Generation and
Derivation typically point upwards.</p>
@@ -605,11 +625,7 @@
</div>
-<p> This simple example has shown a variety of PROV-DM constructs, such as Entity, Agent, Activity, Usage, Generation, Derivation, and ActivityAssociation. In this example, it happens that all entities were already Web resources, with readily available URIs, which we used. We note that some of the resources are public, whereas others have restricted access: provenance statements only make use of their identifiers. When identifiers do not pre-exist, e.g. for activities, then they can be minted, for instance <span class="name">ex:pub2</span>, occuring in the namespace identified by prefix <span class="name">ex</span>.</p>
-
-<div class='note'>
-Need to say something about this example, where all urls are well behaved.
-</div>
+<p> This simple example has shown a variety of PROV-DM constructs, such as Entity, Agent, Activity, Usage, Generation, Derivation, and ActivityAssociation. In this example, it happens that all entities were already Web resources, with readily available URIs, which we used. We note that some of the resources are public, whereas others have restricted access: provenance statements only make use of their identifiers. If identifiers do not pre-exist, e.g. for activities, then they can be minted, for instance <span class="name">ex:pub2</span>, occuring in the namespace identified by prefix <span class="name">ex</span>. We note that the URI scheme developed by W3C is particularly suited for expressing provenance of these reports, since each URI denotes a specific version of a report. It then becomes very easy to relate the various versions, with PROV-DM constructs. </p>
</section>
@@ -636,7 +652,7 @@
</pre>
<p>While this description is about the same report <span class="name"><a href="http://www.w3.org/TR/2011/WD-prov-dm-20111215">tr:WD-prov-dm-20111215</a></span>, its details differ from the author's perspective: it is a document and it has a version number. </p></li>
-<li>There is a editing activity.
+<li>There is an editing activity.
<pre>
activity(ex:edit1,,,[prov:type="edit"])
</pre>
@@ -656,7 +672,7 @@
</pre>
</li>
-<li>The activity required a publication request: this is a <a title="concept-usage">Usage</a>.
+<li>Agents were assigned various responsibilities in the editing activity: contributor and editor.
<pre>
wasAssociatedWith(ex:edit1, ex:Paolo, [prov:role="editor"])
wasAssociatedWith(ex:edit1, ex:Simon, [prov:role="contributor"])
@@ -681,7 +697,7 @@
who the provenance is attributed to, and when it was
generated, etc. In other words, we need to be able to express the provenance of provenance.</p>
-<p>No new mechanism is required. PROV-DM only assumes that provenance statements have been bundled up, and named. For instance, in this case, provenance statements were put in a file and exposed on the Web, respectively at <a href="http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/examples/w3c-publication1.prov-asn">ex:prov1</a> and <a href="http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/examples/w3c-publication3.prov-asn">ex:prov3</a>. To express their respective provenance, these resources must be seen as entities, and all the constructs of PROV-DM are now available to characterize their provenance. In the example below, <span class="name">ex:prov1</span> is attributed to the agent <span class="name">w3:Consortium</span>, whereas <span class="name">ex:prov3</span> to <span class="name">ex:Simon</span>.
+<p>No new mechanism is required to support this requirement. PROV-DM makes the assumption that provenance statements have been bundled up, and named, by some mechanism outside the scope of PROV-DM. For instance, in this case, provenance statements were put in a file and exposed on the Web, respectively at <a href="http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/examples/w3c-publication1.prov-asn">ex:prov1</a> and <a href="http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/examples/w3c-publication3.prov-asn">ex:prov3</a>. To express their respective provenance, these resources must be seen as entities, and all the constructs of PROV-DM are now available to characterize their provenance. In the example below, <span class="name">ex:prov1</span> is attributed to the agent <span class="name">w3:Consortium</span>, whereas <span class="name">ex:prov3</span> to <span class="name">ex:Simon</span>.
<pre>
entity(ex:prov1, [prov:type="prov:AccountEntity" %% xsd:QName ])
@@ -701,6 +717,11 @@
<h2>PROV-DM Core</h2>
+<p>In this section, we revisit each concept introduction in <a href='#conceptualization'>Section 2</a>, and provide its detailed definition in the PROV data model, in terms of its various constituents. </p>
+
+<p>In PROV-DM, we distinguish elements from relations, which are respectively discussed in
+<a href='#term-element'>Section 4.1</a> and <a href='#term-relation'>Section 4.2</a>.</p>
+
<section id="term-element">
<h3>Element</h3>
@@ -718,13 +739,20 @@
<div class="anexample">
<p>
-The following entity,</p>
+The following expression</p>
<pre class="codeexample">
+entity(tr:WD-prov-dm-20111215, [ prov:type="document", ex:version="2" ])
+</pre>
+states the existence of an entity, denoted by identifier <span class="name">tr:WD-prov-dm-20111215</span>, with type <span class="name">document</span> and version number <span class="name">2</span>. The attributes <span class="name">ex:version</span> is application specific, whereas the attribute <span
+class="name">type</span> is reserved in the PROV-DM namespace.
+<!--The following expression</p>
+<pre class="codeexample">
+entity(tr:WD-prov-dm-20111215, [ prov:type="document", ex:version="2" ])
entity(e0, [ prov:type="File", ex:path="/shared/crime.txt", ex:creator="Alice" ])
</pre>
states the existence of an entity, denoted by identifier <span class="name">e0</span>, with type <span class="name">File</span> and path <span class="name">/shared/crime.txt</span> in the
file system, and creator alice. The attributes <span class="name">path</span> and <span class="name">creator</span> are application specific, whereas the attribute <span
-class="name">type</span> is reserved in the PROV-DM namespace.
+class="name">type</span> is reserved in the PROV-DM namespace.-->
</div>
<p>Further considerations:</p>
@@ -756,9 +784,9 @@
<p> An activity<span class="withAsn">, written <span class="name">activity(id, st, et, [ attr1=val1, ...])</span> in PROV-ASN,</span> contains:</p>
<ul>
<li><em>id</em>: an identifier identifying an activity;</li>
-<li><em>startTime</em>: an OPTIONAL time marking the start of the activity;</li>
-<li><em>endTime</em>: an OPTIONAL time marking the end of the activity;</li>
-<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs, representing attributes of this activity.</li>
+<li><em>startTime</em>: an OPTIONAL time for the start of the activity;</li>
+<li><em>endTime</em>: an OPTIONAL time for the end of the activity;</li>
+<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs for this activity.</li>
</ul>
<div class="anexample">
@@ -769,8 +797,7 @@
[ex:host="server.example.org",prov:type="ex:edit" %% xsd:QName])
</pre>
<p>states the existence of an activity with identifier <span class="name">a1</span>, start time <span class="name">2011-11-16T16:05:00</span>, and end time <span
-class="name">2011-11-16T16:06:00</span>, running on host <span class="name">server.example.org</span>, and of type <span class="name">edit</span> (declared in some namespace with prefix
-<span class="name">ex</span>). The attribute <span class="name">host</span> is application specific, but MUST hold for the duration of activity. The attribute <span
+class="name">2011-11-16T16:06:00</span>, running on host <span class="name">server.example.org</span>, and of type <span class="name">edit</span>. The attribute <span class="name">host</span> is application specific (declared in some namespace with prefix <span class="name">ex</span>). The attribute <span
class="name">type</span> is a reserved attribute of PROV-DM, allowing for subtyping to be expressed.</p>
</div>
@@ -822,10 +849,11 @@
<div class="anexample">
-The following expression is about an agent identified by <span class="name">e1</span>, which is a person, named Alice, with employee number 1234.
+<p>The following expression is about an agent identified by <span class="name">e1</span>, which is a person, named Alice, with employee number 1234.</p>
<pre class="codeexample">
agent(e1, [ex:employee="1234", ex:name="Alice", prov:type="prov:Person" %% xsd:QName])
</pre>
+<p>It is optional to specify the type of an agent. When present, it is expressed using the <span class="name">prov:type</span> attribute.</p>
</div>
<div class='issue'> Shouldn't we allow for entities (not agent) to be associated with an activity? Should we drop the inference association-agent? <a
@@ -837,8 +865,8 @@
<h4>Note</h4>
-<p>As provenance descriptions are exchanged between systems, it may be useful to add extra-information about such descriptions. For instance, a "trust service" may add value-judgements about the
-trustworthiness of some of the descriptions. Likewise, an interactive visualization component may want to enrich a set of provenance descriptions with information helping reproduce their
+<p>As provenance descriptions are exchanged between systems, it may be useful to add extra-information to what they are describing. For instance, a "trust service" may add value-judgements about the
+trustworthiness of some of the entities or agents involved. Likewise, an interactive visualization component may want to enrich a set of provenance descriptions with information helping reproduce their
visual representation. To help with inter-operability, PROV-DM introduces a simple annotation mechanism allowing anythig that is identifiable to be associated with notes.</p>
<p>A <dfn title="dfn-note">note</dfn><span class="withAsn">, noted <span class="name">note(id, [ attr1=val1, ...])</span> in PROV-ASN,</span> contains:</p>
@@ -850,8 +878,8 @@
-<p>A separate PROV-DM construct is used to associate a note with something that is identifiable (see <a href="#term-annotation">Section on annotation</a>). A given note may be associated with
-multiple asssertions.
+<p>A separate PROV-DM relation is used to associate a note with something that is identifiable (see <a href="#term-annotation">Section on annotation</a>). A given note may be associated with
+multiple identifiable things.
</p>
@@ -865,10 +893,16 @@
hasAnnotation(tr:WD-prov-dm-20111215,ex:n1)
</pre>
<p>The note is associated with the entity <span class="name">tr:WD-prov-dm-20111215</span> previously introduced (<a title="annotation">hasAnnotation</a> is
-discussed in Section <a href="#term-annotation">Annotation</a>). In this example,
-the attribute-value pairs do not constitute a representation of something
-in the world; they are just used to help render provenance.
+discussed in Section <a href="#term-annotation">Annotation</a>).
</p>
+
+<p>Alternatively, a reputation service may enrich a provenance record with notes providing reputation ratings about agents. In the following fragment, both agents <span class="name">ex:Simon</span> and <span class="name">ex:Paolo</span> are rated "excellent".</p>
+<pre class="codeexample">
+note(ex:n2,[ex:reputation:"excellent"])
+hasAnnotation(ex:Simon,ex:n2)
+hasAnnotation(ex:Paolo,ex:n2)
+</pre>
+
</div>
@@ -888,11 +922,11 @@
<table border="1" style="margin-left: auto; margin-right: auto;">
<caption>PROV-DM Core Relation Summary</caption>
<tr><td></td><td>Entity</td><td>Activity</td><td>Agent</td><td>Note</td></tr>
-<tr><td>Entity</td><td><a title="derivations">wasDerivedFrom</a><br><a title="alternate">alternateOf</a><br><a title="specialization record">specializationOf</a></td><td><a
-title="generation">wasGeneratedBy</a></td><td>—</td><td><a title="annotation">hasAnnotation</a></td></tr>
-<tr><td>Activity</td><td><a title="usage">used</a></td><td>—</td><td><a title="start record">wasStartedBy</a><br><a title="end record">wasEndedBy</a><br><a title="activity association">wasAssociatedWith</a></td><td><a title="annotation">hasAnnotation</a></td></tr>
-<tr><td>Agent</td><td>—</td><td>—</td><td><a title="responsibility chain">actedOnBehalfOf</a></td><td><a title="annotation">hasAnnotation</a></td></tr>
-<tr><td>Note</td><td>—</td><td>—</td><td>—</td><td><a title="annotation">hasAnnotation</a></td></tr>
+<tr><td>Entity</td><td><a title="derivations">wasDerivedFrom</a><br><a title="dfn-alternate">alternateOf</a><br><a title="dfn-specialization">specializationOf</a></td><td><a
+title="dfn-Generation">wasGeneratedBy</a></td><td>—</td><td><a title="dfn-annotation">hasAnnotation</a></td></tr>
+<tr><td>Activity</td><td><a title="usage">used</a></td><td>—</td><td><a title="start record">wasStartedBy</a><br><a title="end record">wasEndedBy</a><br><a title="dfn-activity-association">wasAssociatedWith</a></td><td><a title="dfn-annotation">hasAnnotation</a></td></tr>
+<tr><td>Agent</td><td>—</td><td>—</td><td><a title="dfn-responsibility-chain">actedOnBehalfOf</a></td><td><a title="dfn-annotation">hasAnnotation</a></td></tr>
+<tr><td>Note</td><td>—</td><td>—</td><td>—</td><td><a title="dfn-annotation">hasAnnotation</a></td></tr>
</table>
</div>
@@ -907,7 +941,7 @@
<p><dfn title="dfn-Generation">Generation</dfn><span class="withAsn">, written <span class="name">wasGeneratedBy(id,e,a,t,attrs)</span> in PROV-ASN,</span> has the following components:</p>
<ul>
-<li><em>id</em>: an OPTIONAL identifier identifying the generation;</li>
+<li><em>id</em>: an OPTIONAL identifier identifying a generation;</li>
<li><em>entity</em>: an identifier identifying a created entity; </li>
<li><em>activity</em>: an OPTIONAL identifier identifying the activity that creates the entity;</li>
@@ -915,7 +949,7 @@
<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs that describes the modalities of generation of this entity by this activity.</li>
</ul>
-<p>While the components <em>activity</em>, <em>time</em>, and <em>attributes</em> are OPTIONAL, at least one of them MUST be present.</p>
+<p>While each of the components <em>activity</em>, <em>time</em>, and <em>attributes</em> is OPTIONAL, at least one of them MUST be present.</p>
@@ -945,12 +979,6 @@
</pre>
</div>
-<div class='note'>
-<p>?????????
-A generation's id is OPTIONAL. It MUST be used when annotating generations (see Section <a href="#term-annotation">Annotation Record</a>) or when defining precise-1
-derivations (see <a href="#Derivation-Relation">Derivation Record</a>).
-</p>
-</div>
<div class='pending'> We may want to assert the time at which an entity is created. The placeholder for such time information is a generation record. But a generation mandates the presence of an activity identifier. But it may not be known.
It would be nice if the activity identifier was made optional in the generation record.
@@ -967,7 +995,7 @@
<p><dfn title="dfn-Usage">Usage</dfn><span class="withAsn">, written <span class="name">used(id,a,e,t,attrs)</span> in PROV-ASN,</span> has the following constituents:</p>
<ul>
-<li><em>id</em>: an OPTIONAL identifier identifying the usage;</li>
+<li><em>id</em>: an OPTIONAL identifier identifying a usage;</li>
<li><em>activity</em>: an identifier for the consuming activity;</li>
<li><em>entity</em>: an identifier for the consumed entity;</li>
<li><em>time</em>: an OPTIONAL "usage time", the time at which the entity started to be used;</li>
@@ -986,7 +1014,7 @@
used(a1,e1,2011-11-16T16:00:00,[ex:parameter="p1"])
used(a1,e2,2011-11-16T16:00:01,[ex:parameter="p2"])
</pre>
-<p>state that the activity identified by <span class="name">a1</span>, consumed two entities identified by <span
+<p>state that the activity identified by <span class="name">a1</span> consumed two entities identified by <span
class="name">e1</span> and <span class="name">e2</span>, at times <span class="name">2011-11-16T16:00:00</span> and <span class="name">2011-11-16T16:00:01</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> is application specific.</p>
@@ -1020,8 +1048,8 @@
<h4>Activity Association</h4>
-<p>As far as responsibility is concerned, PROV-DM offers two kinds of constructs. The first, introduced in this section, represents an association between an agent, a plan, and an activity; the second, introduced in <a
-href="#term-responsibility">Section Responsibility</a>, represents the fact that an agent was acting on behalf of another, in the context of an activity. </p>
+<p>As far as responsibility is concerned, PROV-DM offers two kinds of constructs. The first, introduced in this section, is relation between an agent, a plan, and an activity; the second, introduced in <a
+href="#term-responsibility">Section Responsibility</a>, is a relation between agents expressing that an agent was acting on behalf of another, in the context of an activity. </p>
<p>An <dfn title="dfn-activity-association">activity association</dfn><span class="withAsn">, written <span class="name">wasAssociatedWith(id,a,ag2,pl,attrs)</span> in PROV-ASN,</span> has the following
@@ -1030,7 +1058,7 @@
<li><em>id</em>: an OPTIONAL identifier for the association between an activity and an agent;</li>
<li><em>activity</em>: an identifier for the activity;</li>
<li><em>agent</em>: an identifier for the agent associated with the activity;</li>
-<li><em>plan</em>: an OPTIONAL identifier for an entity, which is the plan adopted by the agent in the context of this activity;
+<li><em>plan</em>: an OPTIONAL identifier for the plan adopted by the agent in the context of this activity;
<li><em>attributes</em>: an OPTIONAL set of attribute-value pairs that describe the modalities of association of this activity with this agent.</li>
</ul>
@@ -1117,7 +1145,7 @@
<h4>Responsibility Chain</h4>
-<p>To promote take-up, PROV-DM offers a mild version of responsibility
+<p>PROV-DM offers a mild version of responsibility
in the form of a relation to represent when an agent acted on another
agent's behalf. So in the example of someone running a mail program,
the program is an agent of that activity and the person is also an
@@ -1126,7 +1154,7 @@
student acted on behalf of his supervisor, who acted on behalf of the
department chair, who acts on behalf of the university, and all those
agents are responsible in some way for the activity to take place but
-we don't say explicitly who bears responsibility and to what
+we do not say explicitly who bears responsibility and to what
degree. </p>
<p>We could also say that an agent can act on behalf of several other
@@ -1140,8 +1168,7 @@
might be a need to define specific aspects of control that various
agents exert over a given activity.</p>
-<p>Given an activity association<span class="withAsn">, written <span class="name">wasAssociatedWith(a,ag2,attrs)</span></span>,
-a <dfn title="dfn-responsibility">responsibility chain</dfn><span class="withAsn">, written <span class="name">actedOnBehalfOf(id,ag2,ag1,a,attrs)</span> in PROV-ASN,</span> has the following constituents:</p>
+<p>A <dfn title="dfn-responsibility-chain">responsibility chain</dfn><span class="withAsn">, written <span class="name">actedOnBehalfOf(id,ag2,ag1,a,attrs)</span> in PROV-ASN,</span> has the following constituents:</p>
<ul>
<li><em>id</em>: an OPTIONAL identifier <span class="name">id</span> identifying the responsibility chain;</li>
<li><em>subordinate</em>: an identifier for the agent associated with an activity, acting on behalf of the responsible
@@ -1175,7 +1202,7 @@
<h4>Derivation</h4>
<div class='note'>
-Using asserter/assertion.
+This text was not edited much. It keeps on referring to asserter/assertion. Before editing this section, we would like to have <a href="http://www.w3.org/2011/prov/track/issues/249">ISSUE-249</a> resolved.</div>
</div>
@@ -1234,7 +1261,7 @@
When <span class="name">prov:steps="single"</span>, derivation is due to one activity; when <span class="name">prov:steps="any"</span>, the number of activities is multiple or not known.</p>
-<p>The three kinds of <dfn title="dfn-derivation">derivations</dfn> are successively introduced. Making use of the attribute <span class="name">steps</span>, we can distinguish the various derivation types.</p>
+<p>The three kinds of <dfn id="dfn-derivation">derivations</dfn> are successively introduced. Making use of the attribute <span class="name">steps</span>, we can distinguish the various derivation types.</p>
<p>A <dfn>precise-1 derivation</dfn><span class="withAsn">, written <span class="name">wasDerivedFrom(id, e2, e1, a, g2, u1, attrs)</span> in PROV-ASN,</span> contains:</p>
<ul>
@@ -1323,7 +1350,7 @@
<h4>Alternate and Specialization</h4>
-<p>The purpose of this section is to introduce relations between two entities that provide different characterizations for the same thing.
+<p>The purpose of this section is to introduce relations between two entities that refer to the same thing in the world.
Consider for example three entities:
</p>
<ul>
@@ -1338,13 +1365,13 @@
<ol>
- <li>e1 and e2 describe Bob from two different perspectives (as facebook and twitter users, respectively)
- <li> both of e1 and e2 provide a more concrete perspective on Bob than e1 does (each of them provides more details).
+ <li>e1 and e2 refer to Bob in two contexts (as facebook and twitter users, respectively)
+ <li> both of e1 and e2 are more detailed then than e3.
</ol>
-<p>The following two relations are introduced for expressing alternative or specialized characterisations. </p>
+<p>The following two relations are introduced for expressing alternative or specialized entities. </p>
@@ -1353,18 +1380,18 @@
<ul>
<li><em>id</em>: an OPTIONAL identifier for the association between the two alternates;</li>
-<li><em>first alternate</em>: an identifier <span class="name">alt1</span> of the first of the two entities</li>
-<li><em>second alternate</em>: an identifier <span class="name">alt2</span> of the second of the two entities</li>
-<li><em>attrs</em>: an OPTIONAL set <span class="name">attrs</span> of attribute-value pairs to further describe this relation.</li>
+<li><em>firstAlternate</em>: an identifier of the first of the two entities;</li>
+<li><em>secondAlternate</em>: an identifier of the second of the two entities;</li>
+<li><em>attrs</em>: an OPTIONAL set of attribute-value pairs to further describe this relation.</li>
</ul>
-<p>A <dfn title="dfn-Specialization">specialization relation</dfn><span class="withAsn">, written <span class="name">specializationOf([id], sub, super, [attrs])</span> in PROV-ASN,</span> addresses case (2). It has the following constituents:</p>
+<p>A <dfn title="dfn-Specialization">specialization relation</dfn><span class="withAsn">, written <span class="name">specializationOf(id, sub, super, attrs)</span> in PROV-ASN,</span> addresses case (2). It has the following constituents:</p>
<ul>
<li><em>id</em>: an OPTIONAL identifier for the association between the two entities;</li>
-<li><em>specialised entity</em>: an identifier of the specialised entity</li>
-<li><em>general entity</em>: an identifier of the entity that is being specialised</li>
+<li><em>specializedEntity</em>: an identifier of the specialised entity;</li>
+<li><em>generalEntity</em>: an identifier of the entity that is being specialised;</li>
<li><em>attrs</em>: an OPTIONAL set of attribute-value pairs to further describe this relation.</li>
</ul>