removed the respeced version
authorPaul Groth <p.t.groth@vu.nl>
Mon, 16 Jul 2012 12:06:56 +0200
changeset 4073 c750c874d5ac
parent 4072 02b91d2b1497
child 4074 7c32b80d4228
removed the respeced version
primer/WD-prov-primer-20120724/Primer.html
--- a/primer/WD-prov-primer-20120724/Primer.html	Mon Jul 16 12:02:48 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1248 +0,0 @@
-<!DOCTYPE html>
-<html>
- <head> 
-  <title>PROV Model Primer</title>
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-    "PROV-DM":
-     "Luc Moreau, Paolo Missier"+
-     "<a href=\"http://www.w3.org/TR/prov-dm/\"><cite>The PROV Data Model and Abstract Syntax Notation</cite></a>. "+
-     "Working Draft, "+
-     "URL: <a href=\"http://www.w3.org/TR/prov-dm/\">http://www.w3.org/TR/prov-dm/</a>",
-
-    "PROV-O":
-     "Satya Sahoo, Deborah McGuinness"+
-     "<a href=\"http://www.w3.org/TR/prov-o/\"><cite>The PROV Ontology: Model and Formal Semantics</cite></a>. "+
-     "Working Draft, "+
-     "URL: <a href=\"http://www.w3.org/TR/prov-o/\">http://www.w3.org/TR/prov-o/</a>",
-    
-    "PROV-N":
-     "Luc Moreau, Paolo Missier"+
-     "<a href=\"http://www.w3.org/TR/prov-n/\"><cite>PROV-N: The PROV Notation</cite></a>. "+
-     "Working Draft, "+
-     "URL: <a href=\"http://www.w3.org/TR/prov-n/\">http://www.w3.org/TR/prov-n/</a>",
-
-    "PROV-AQ":
-     "Graham Klyne, Paul Groth"+
-     "<a href=\"http://www.w3.org/TR/prov-aq/\"><cite>PROV-AQ: Provenance Access and Query</cite></a>. "+
-     "Working Draft, "+
-     "URL: <a href=\"http://www.w3.org/TR/prov-aq/\">http://www.w3.org/TR/prov-aq/</a>",
-
-    "PROV-CONSTRAINTS":
-     "James Cheney, Paolo Missier, Luc Moreau"+
-     "<a href=\"http://www.w3.org/TR/prov-constraints/\"><cite>Constraints of the Provenance Data Model</cite></a>. "+
-     "Working Draft, "+
-     "URL: <a href=\"http://www.w3.org/TR/prov-constraints/\">http://www.w3.org/TR/prov-constraints/</a>",
-
-    "TURTLE":
-     "Eric Prud'hommeaux, Gavin Carothers"+
-     "<a href=\"http://www.w3.org/TR/2011/WD-turtle-20110809/\"><cite>Turtle: Terse RDF Triple Language</cite></a>. "+
-     "9 August 2011. W3C Working Draft. "+
-     "URL: <a href=\"http://www.w3.org/TR/2011/WD-turtle-20110809/\">http://www.w3.org/TR/2011/WD-turtle-20110809/</a>",
-    
-    "PROVENANCE-XG":
-     "Yolanda Gil, James Cheney, Paul Groth, Olaf Hartig, Simon Miles, Luc Moreau, Paulo Pinheiro da Silva"+
-     "<a href=\"http://www.w3.org/2005/Incubator/prov/XGR-prov/\"><cite>Provenance XG Final Report</cite></a>. "+
-     "8 December 2010. "+
-     "URL: <a href=\"http://www.w3.org/2005/Incubator/prov/XGR-prov/\">http://www.w3.org/2005/Incubator/prov/XGR-prov/</a>"
-    };
-   
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-    shortName:            "prov-primer",
- 
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- 
-    // editors, add as many as you like
-    // only "name" is required
-    editors:  [
-     { name: "Yolanda Gil", url: "http://www.isi.edu/~gil/",
-      company: "Information Sciences Institute, University of Southern California, US" },
-     { name: "Simon Miles", url: "http://www.inf.kcl.ac.uk/staff/simonm",
-      company: "King's College London, UK" },
-    ],
- 
-    // authors, add as many as you like.
-    // This is optional, uncomment if you have authors as well as editors.
-    // only "name" is required. Same format as editors.
- 
-    authors:  [
-     { name: "<a href=\"http://semanticweb.org/wiki/Khalid_Belhajjame\">Khalid Belhajjame</a>",
-      company: "University of Manchester" },
-     { name: "Helena Deus",
-      company: "Digital Enterprise Research Institute (DERI), NUI Galway" },
-     { name: "<a href=\"http://www.oeg-upm.net/index.php/en/phdstudents/28-dgarijo\">Daniel Garijo</a>",
-      company: "Universidad Politécnica de Madrid" },
-     { name: "Graham Klyne",
-      company: "University of Oxford" },
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-      company: "Newcastle University" },
-     { name: "<a href=\"http://soiland-reyes.com/stian/\">Stian Soiland-Reyes</a>",
-      company: "University of Manchester" },
-     { name: "<a href=\"http://tw.rpi.edu/web/person/StephanZednik\">Stephan Zednik</a>",
-      company: "Rensselaer Polytechnic Institute" },
-    ],
-          
-    // name of the WG
-    wg:           "Provenance Working Group",
-          
-    // URI of the public WG page
-    wgURI:        "http://www.w3.org/2011/prov/",
-          
-    // name (with the @w3c.org) of the public mailing to which comments are due
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-          
-    // URI of the patent status for this WG, for Rec-track documents
-    // !!!! IMPORTANT !!!!
-    // This is important for Rec-track documents, do not copy a patent URI from a random
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-    // Team Contact.
-    wgPatentURI:  "http://www.w3.org/2004/01/pp-impl/46974/status",
-    
-    // Add extraReferences to bibliography database
-    preProcess: [addExtraReferences]
-   };
-  </script>
- </head>
- <body>
-  <section id="abstract">
-   <p>
-    This document provides an intuitive introduction and guide to the
-    PROV specification for provenance on the Web. PROV is a core data model for
-    provenance for building representations of the entities, people and
-    processes involved in producing a piece of data or thing in the world.
-    This primer explains the fundamental PROV concepts and provides examples 
-    of its use.  The primer is intended as a starting point for those wishing
-    to create or use PROV data.
-   </p>
-
-   <!-- p>
-    This is a document for internal discussion, which will ultimately
-    evolve in the first Public Working Draft of the Primer.</p -->
-  </section> 
-
-  <section id="sotd">
-   This document is part of a set of specifications aiming to define the
-   various aspects that are necessary to achieve the vision of
-   interoperable interchange of provenance information in heterogeneous
-   environments such as the Web. This document is an
-   intuitive introduction and guide with simple illustrative examples
-   of the core aspects of PROV.
-
-   <h4>PROV Family of Specifications</h4>
-   The PROV family of specifications aims to define the various aspects that are necessary to achieve the vision of inter-operable
-   interchange of provenance information in heterogeneous environments such as the Web.  
-   The specifications are as follows.
-   <ul>
-    <li> PROV-PRIMER, a primer for the PROV data model (this document),</li>
-    <li> PROV-DM, the PROV data model for provenance,</li>
-    <li> PROV-DM-CONSTRAINTS, a set of constraints applying to the PROV data model,</li>
-    <li> PROV-N, a notation for provenance aimed at human consumption,</li>
-    <li> PROV-O, the PROV ontology, an OWL-RL ontology allowing the mapping of PROV to RDF;</li>
-    <li> PROV-AQ, the mechanisms for accessing and querying provenance; </li>
-    <li> PROV-SEM, a formal semantics for the PROV data model.</li>
-    <li> PROV-XML, an XML schema for the PROV data model.</li>
-   </ul>
-   <h4>How to read the PROV Family of Specifications</h4>
-   <ul>
-    <li>The primer is the entry point to PROV offering a pedagogical presentation of the provenance model.</li>
-    <li>The Linked Data and Semantic Web community should focus on PROV-O defining PROV classes and properties specified in an OWL-RL ontology. For further details, PROV-DM and PROV-DM-CONSTRAINTS specify the constraints applicable to the data model, and its interpretation. PROV-SEM provides a mathematical semantics.</li>
-    <li>The XML community should focus on PROV-XML defining an XML schema for PROV-DM. Further details can also be found in PROV-DM, PROV-DM-CONSTRAINTS, and PROV-SEM.</li>
-    <li>Developers seeking to retrieve or publish provenance should focus of PROV-AQ.</li>
-    <li>Readers seeking to implement other PROV serializations
-     should focus on PROV-DM and PROV-DM-CONSTRAINTS.  PROV-O, PROV-N, PROV-XML offer examples of mapping to RDF, text, and XML, respectively.</li>
-   </ul>
-
-
-  </section>
-
-  <section> 
-   <h2>Introduction</h2>
-   <p>
-    This primer document provides an accessible introduction to the PROV 
-    specification for provenance on the Web.  
-    The <i>provenance</i> of digital objects represents their origins.  PROV is a 
-    proposed specification to express provenance records, 
-    which contain <i>descriptions</i> of the entities 
-    and activities involved in producing and delivering or otherwise influencing a 
-    given object.
-    For the remainder of this document, we use the term 'provenance' to refer also
-    to records of provenance, except where the distinction is important for clarity.
-    By knowing the provenance of an object, we can perceive how to
-    use it.  Provenance can be used for many purposes, such as 
-    understanding how data was collected so it can be meaningfully used, determining 
-    ownership and rights over an object, making judgments about information to 
-    determine whether to trust it, verifying that the process and steps used to obtain a 
-    result complies with given requirements, and reproducing how something was generated.
-   </p>
-
-   <p>
-    As a specification for provenance, PROV accommodates all those different uses 
-    of provenance.  Different people may have different perspectives on provenance, 
-    and as a result different types of information might be captured in provenance records.
-   <ul>
-    <li>
-     One perspective might focus on <i>agent-centered provenance</i>, that is, what entities 
-     were involved in generating or manipulating the information in question.  For example, 
-     in the provenance of a picture in a news article we might capture the photographer who 
-     took it, the person that edited it, and the newspaper that published it.
-    </li>
-    <li>
-     A second perspective 
-     might focus on <i>object-centered provenance</i>, by tracing the origins of portions of a 
-     document to other documents. An example is having a web page that was assembled from content
-     from a news article, quotes of interviews with experts, and a chart that plots data from a 
-     government agency.
-    </li>
-    <li>A third perspective one might take is on <i>process-centered provenance</i>, 
-     capturing the actions and steps taken to generate the information in question.  For example, a 
-     chart may have been generated by invoking a service to retrieve data from a database, then 
-     extracting certain statistics from the data using some statistics package, and finally 
-     processing these results with a graphing tool.
-    </li>
-   </ul>
-  </p>
-
-  <p>
-   Provenance records are metadata.  There are other kinds of metadata that is 
-   not provenance.  For example, the size of an image is metadata of 
-   that image but it is not provenance.
-   For general background on provenance, a 
-   comprehensive overview of requirements, use cases, prior research, and proposed 
-   vocabularies for provenance are available from the 
-   Final Report of the W3C Provenance Incubator Group [[PROVENANCE-XG]].
-   That document contains three general scenarios 
-   that may help identify the provenance aspects of planned applications and 
-   help plan the design of a provenance system.
-  </p>
-
-  <p>
-   This primer document aims to ease the adoption of the PROV specifications by providing:
-  </p>
-  <ul>
-   <li>An intuitive explanation of how PROV models provenance. A detailed description of
-    all the concepts and relations in the PROV Data Model is provided in [[PROV-DM]].</li>
-   <li>A simple self-contained example that illustrates how to produce and use PROV assertions, highlighting how 
-    to combine PROV with other popular vocabularies such as FOAF and Dublin Core.  A description
-    of the formal PROV ontology (PROV-O) can be found in [[PROV-O]].</li>
-   <li>Example snippets using a notation of PROV designed for human
-    consumption (PROV-N).  Details of this notation can be found at [[PROV-N]].</li>
-  </ul>
-
-  <p>There are additional reference documents for PROV that are not covered in this 
-   primer, including the PROV Access and Query aspects of the specification [[PROV-AQ]], 
-   the constraints on the PROV data model [[PROV-CONSTRAINTS]], 
-   a formal semantics of the PROV data model (PROV-SEM), and the PROV XML notation 
-   (PROV-XML). </p>
-
- </section>
-
- <section>
-  <h2>Intuitive overview of PROV</h2>
-
-  <p>
-   This section provides an intuitive explanation of the main concepts in PROV. 
-   As with the rest of this document, it should be treated as a starting point for
-   understanding the model. The PROV data model document [[PROV-DM]]
-   provides precise definitions and constraints [[PROV-CONSTRAINTS]] to be used.
-  </p>
-  <p>
-   The following diagram provides a high level overview of the structure of PROV records,
-   limited to some key PROV concepts discussed in this document.
-   The diagram is the same that appears in the [[PROV-DM]] document.
-   Note that because PROV is meant to describe how things were created or delivered, 
-   PROV relations are named so they can be used in assertions about the past.  
-  </p>
-
-  <div style="text-align: center;">
-   <img src="OverviewDiagram.png" alt="PROV-DM overview"/>
-  </div>
-
-  <section>
-   <h3>Entities</h3>
-
-   <p>
-    In PROV, physical, digital, conceptual, or other kinds of thing are called
-    <i>entities</i>.
-    Examples of such entities are a web page, a chart, and a spellchecker.
-    Provenance records can describe the provenance of entities, and
-    an entity’s provenance may refer to many other entities.  For example, a document D is
-    an entity whose provenance refers to other entities such as a chart inserted into D,
-    and the dataset that was used to create that chart.
-    Entities may be described as having different attributes and
-    be described from different perspectives.  For example,
-    document D as stored in my file system, the second version of document D, 
-    and D as an evolving document,
-    are three distinct entities for which we may describe provenance.
-   </p>
-  </section>
-
-  <section>
-   <h3>Activities</h3>
-
-   <p>
-    <i>Activities</i> are how entities come into 
-    existence and how their attributes change to become new entities, 
-    often making use of previously existing entities to achieve this. 
-    They are
-    dynamic aspects of the world, such as actions, processes, etc.
-    For example, if the second version of document D was generated 
-    by a translation from the first version of the document in another language,
-    then this translation is an activity.
-   </p>Use
-  </section>
-
-  <section>
-   <h3>Usage and Generation</h3>
-   <p>
-    Activities <i>generate</i> new entities.
-    For example, writing a document brings the document into existence, while
-    revising the document brings a new version into existence.
-    Activities also make <i>use</i> of entities. For example, revising a document
-    to fix spelling mistakes uses the original version of the document as well
-    as a list of corrections.
-    Generation does not always occur at the end of an activity, and an activity may generate entities
-    part-way through.
-    Likewise, usage does not always occur at the beginning of an activity.
-   </p>
-  </section>
-
-  <section>
-   <h3>Agents and Responsibility</h3>
-   <p>
-    An <i>agent</i> takes a role in an activity such 
-    that the agent can be assigned some degree of <i>responsibility</i> for the activity taking 
-    place.
-    An agent can be a person, a piece of software, an inanimate object, an organization, or
-    other entities that may be ascribed responsibility.
-    When an agent has some responsibility for an activity, PROV says the agent was
-    <i>associated</i> with the activity, where several agents may be associated with
-    an activity and vice-versa.
-    Consider a chart displaying some statistics 
-    regarding crime rates over time in a linear regression.  To represent the 
-    provenance of that chart, we could state that the person who created the 
-    chart was an agent involved in its creation, and that the software used to 
-    create the chart was also an agent involved in that activity.
-    An agent may be <i>acting on behalf</i> of others, e.g. an employee on behalf of their
-    organization, and we can express such chains of responsibility in the provenance.
-   </p>
-   <p>
-    We can also describe that an entity is <i>attributed</i> to an agent to express
-    the agent's responsibility for that entity, possibly along with other agents.
-    This description can be understood as a shorthand
-    for saying that the agent was responsible for the activity which generated
-    the entity.
-   </p>
-   <p>
-    One may want to describe the provenance of an agent.  For example, an organization 
-    responsible for the creation of a report may evolve over time as the report is written as
-    some members leave and others join.  To make provenance assertions about an agent in PROV ,
-    the agent must be declared explicitly both as an agent and as an entity.
-   </p>
-
-  </section>
-
-  <section>
-   <h3>Roles</h3>
-   <p>
-    A <i>role</i> is a description of the function or the part that an entity 
-    played in an activity.  Roles specify
-    the relationship between an entity and an activity, i.e. how
-    the activity used or generated the entity.  Roles also specify how agents are
-    involved in an activity, qualifying their participation in the activity or
-    specifying for what aspect of it each agent was responsible.
-    For example, an agent may play the role of "editor" in an activity that uses
-    one entity in the role of "document to be edited" and another in the role of
-    "addition to be made to the document", to generate a further entity in the role of "edited document".
-    Roles are application specific, so PROV does not define any particular roles.
-   </p>
-   <!--p>Roles are intended as an extension point in the model; it is expected users will define and use custom role taxonomies.  Role interpretation is application specific.</p -->
-  </section>
-
-  <section>
-   <h3>Derivation and Revision</h3>
-   <p>
-    When one entity's existence, content, characteristics and so on are
-    at least partly due to another entity, then we say that the former was
-    <i>derived</i> from the latter. For example, one document may contain
-    material copied from another, 
-    and a chart was derived from the data that it illustrates.
-   </p>
-   <p>
-    PROV allows some common, specialized kinds of derivation to be described.
-    For example, a given entity, such as a document, may go through multiple <i>revisions</i> 
-    over time. Between revisions,
-    one or more attributes of the entity may change. 
-    In PROV, the result of each revision is a new entity.
-    PROV allows one to relate those entities by making a description that 
-    one was a revision of another.
-    Another specialized kind of derivation is to say that one entity, commonly
-    a document, <i>quotes</i> from another.
-   </p>
-  </section>
-
-  <section>
-   <h3>Plans</h3>
-   <p>
-    Activities may follow pre-defined procedures, such as recipes, tutorials, instructions, or workflows.
-    PROV refers to these, in general, as <i>plans</i>, and allows the description that a plan was followed, by agents,
-    in executing an activity.
-   </p>
-  </section>
-
-  <section>
-   <h3>Time</h3>
-   <p>
-    Time is often a critical aspect of provenance.
-    PROV allows the timing of significant events to be described, including
-    when an entity was generated or used, or when an activity started
-    and finished. For example, the model can be used to describe facts such as when a new
-    version of a document was created (generation time), or when a document was
-    edited (start and end of the editing activity).
-   </p>
-  </section>
-
-  <section>
-   <h3>Alternate Entities and Specialization</h3>
-   <p>
-    Entities are defined in a flexible way in PROV, allowing for different
-    perspectives to be taken as appropriate for the application. The following
-    are examples illustrating this idea.
-   </p>
-   <ul>
-    <li>The same entity can appear with different descriptions in a provenance record
-     because each appearance emphasizes different aspects of the entity, e.g.
-     a book may be described by its title in one place and by its author and publication date
-     in another.</li>
-    <li>The same entity can evolve over time into different 
-     versions, e.g. a document that is repeatedly updated and has 
-     subsequent releases over time.</li>
-    <li>The same entity can be copied 
-     or replicated, e.g. a document may be copied to several directories.</li>
-    <li>An entity can go through different incarnations, e.g.
-     a committee producing a report may have a set of members when the report 
-     is first released and have a different set of members when an update of
-     the report is released.</li>
-   </ul>
-   <p>
-    In all these situations, 
-    the more specific entities (the versions, copies, incarnations) can be said in PROV to be <i>specializations</i>
-    of the more general entity (the book, the document or the committee as a general entity).
-    The specific entities in each example are also <i>alternates</i> of each other, as they are specializations
-    of the same general entity.
-    Being aware that two entities are alternates allows those
-    consuming the PROV data to know that understanding the provenance of one entity is salient
-    to understanding the provenance of the other.  Knowing that alternate entities are 
-    specializations of another allows a consumer of PROV to refer to the general entity
-    with a unique identifier even though it is specified as different alternates 
-    throughout the provenance records.
-   </p>
-  </section>   
-
- </section>
-
- <section>
-  <h2>Examples of Key Concepts in PROV</h2>
-
-  <p>
-   In the following sections, we show how PROV can be used to model 
-   provenance in a specific example scenario. Samples of PROV data are given.
-   These samples use the namespace prefixes <b>prov</b>, denoting 
-   terms from the PROV ontology, and <b>ex</b>, denoting terms specific to the example.
-   We illustrate in these examples how PROV can be used in combination with other
-   languages, such as FOAF and Dublin Core (with namespace prefix <b>foaf</b> and 
-   <b>dcterms</b> respectively).
-  </p>
-  <p>
-   The samples can be displayed in one or more of the following formats.
-  </p>
-  <ul>
-   <li>[[PROV-O]] RDF triples, expressed using the [[TURTLE]] notation.</li>
-   <li>[[PROV-N]] expressions.</li>
-  </ul>
-  <p>
-   Select the formats to display using the buttons below. Note that if all formats
-   are hidden, the worked examples may not make sense!
-  </p>
-  <form action="#"><p> 
-    <input id="hide-turtle-examples" type="button" value="Hide Turtle Examples" 
-           onclick="
-            set_display_by_class('pre','turtle example','none');
-            set_display_by_class('div','turtle example','none');
-            set_display_by_id('hide-turtle-examples','none');
-            set_display_by_id('show-turtle-examples','');" />
-    <input id="show-turtle-examples" type="button" value="Show Turtle Examples"
-           style="display:none"
-           onclick="
-            set_display_by_class('pre','turtle example','');
-            set_display_by_class('div','turtle example','');
-            set_display_by_id('hide-turtle-examples','');
-            set_display_by_id('show-turtle-examples','none');" />
-    <input id="hide-provn-examples" type="button" value="Hide PROV-N Examples"
-           onclick="
-            set_display_by_class('pre','provn example','none');
-            set_display_by_class('div','provn example','none');
-            set_display_by_id('hide-provn-examples','none');
-            set_display_by_id('show-provn-examples','');" />
-    <input id="show-provn-examples" type="button" value="Show PROV-N Examples" 
-           style="display:none"
-           onclick="
-            set_display_by_class('pre','provn example','');
-            set_display_by_class('div','provn example','');
-            set_display_by_id('hide-provn-examples','');
-            set_display_by_id('show-provn-examples','none');" />
-   </p> 
-  </form>
-
-
-  <section>
-   <h3>Entities</h3>
-
-   <p>
-    An online newspaper publishes an article with a chart about crime statistics making using of data (GovData) provided through a government portal. 
-    The article includes a chart based on the data, with data values composed (aggregated) by
-    geographical regions.
-   </p>
-   <p>
-    A blogger, Betty, looking at the article, spots what she thinks to be an error in the chart.
-    Betty retrieves a record of the provenance of the article, describing how it was created.
-   </p>
-   <p>Betty finds the following descriptions of entities in the provenance.</p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:article     a prov:Entity ;
-                 dcterms:title "Crime rises in cities" .
-  ex:dataset1    a prov:Entity .
-  ex:regionList  a prov:Entity .
-  ex:composition a prov:Entity .
-  ex:chart1      a prov:Entity .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  entity(ex:article, [dcterms:title='Crime rises in cities'])
-  entity(ex:dataSet1)
-  entity(ex:regionList)
-  entity(ex:composition)
-  entity(ex:chart1)
-    </pre>
-   </div>
-   <p>
-    These statements, in order, refer to the article (<code>ex:article</code>),
-    an original data set (<code>ex:dataSet1</code>),
-    a list of regions (<code>ex:regionList</code>), 
-    data aggregated by region (<code>ex:composition</code>), 
-    and a chart (<code>ex:chart1</code>), and state that each is an entity.
-    Any entity may have attributes, such as the title
-    of the article, expressed using <code>dcterms:title</code> above.
-   </p>
-   <p>
-    PROV data is commonly visualized for human consumption using particular conventions,
-    which we will introduce over the following sections. To start with, entities
-    are denoted using ovals, as shown below.
-   </p>
-   <img src="images/entities.png" alt="Visualization of the example entities"/>
-  </section>
-
-  <section>
-   <h3>Activities</h3>
-
-   <p>
-    Further, the provenance describes that there was
-    an activity (<code>ex:compile</code>) denoting the compilation of the
-    chart from the data set.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compile a prov:Activity .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  activity(ex:compile)
-    </pre>
-   </div>
-   <p>
-    The provenance also includes reference to the more specific steps involved in this compilation,
-    which are first composing the data by region (<code>ex:compose</code>) and then generating the
-    chart graphic (<code>ex:illustrate</code>).
-   </p>
-   <!--p>
-    Further, the provenance describes the activities involved in generating chart from the data,
-    first composing the data by region (<code>ex:compose</code>) and then generating the
-    chart graphic (<code>ex:illustrate</code>).
-   </p -->
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose    a prov:Activity .
-  ex:illustrate a prov:Activity .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  activity(ex:compose)
-  activity(ex:illustrate)
-    </pre>
-   </div>
-   <p>
-    In visualizations of the PROV data, activities are depicted as rectangles, as below.
-   </p>
-   <img src="images/activities.png" alt="Visualization of the example activities"/>
-  </section>
-
-  <section>
-   <h3>Usage and Generation</h3>
-
-   <p>
-    Concluding the basic description of what occurred, the provenance 
-    describes the key relations among the above
-    entities and activities, i.e. the usage of an entity by an activity,
-    or the generation of an entity by an activity.
-   </p>
-   <p>
-    For example, the descriptions below state that the composition activity
-    (<code>ex:compose</code>) used the original data set, that it used the list of
-    regions, and that the composed data was generated by this activity.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose      prov:used           ex:dataSet1 ;
-                  prov:used           ex:regionList .
-  ex:composition  prov:wasGeneratedBy ex:compose .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  used(ex:compose, ex:dataSet1, -)
-  used(ex:compose, ex:regionList, -)
-  wasGeneratedBy(ex:composition, ex:compose, -)
-    </pre>
-   </div>
-   <p>
-    Similarly, the chart graphic creation activity (<code>ex:illustrate</code>)
-    used the composed data, and the chart was generated by this activity.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:illustrate prov:used           ex:composition .
-  ex:chart1     prov:wasGeneratedBy ex:illustrate .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  used(ex:illustrate, ex:composition, -)
-  wasGeneratedBy(ex:chart1, ex:illustrate, -)
-    </pre>
-   </div>
-   <p>
-    In visualizing the PROV data, usage and generation are connections between
-    entities and activities. The arrows point from the future to the past.
-   </p>
-   <img src="images/use-generate.png" alt="Connection of the entities and activities by use and generation links"/>
-  </section>
-
-  <section>
-   <h3>Agents and Responsibility</h3>
-
-   <p>
-    Digging deeper, Betty wants to know who compiled the chart.
-    Betty sees that Derek was involved in both the composition and
-    chart creation activities:
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose    prov:wasAssociatedWith ex:derek .
-  ex:illustrate prov:wasAssociatedWith ex:derek .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  wasAssociatedWith(ex:compose, ex:derek, -)
-  wasAssociatedWith(ex:illustrate, ex:derek, -)
-    </pre>
-   </div>
-   <p>
-    The record for Derek provides the
-    following description that
-    Derek is an agent, specifically a person, followed by non-PROV information
-    giving attributes of Derek.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:derek a prov:Agent ;
-           a prov:Person ;
-           foaf:givenName "Derek"^^xsd:string ;
-           foaf:mbox      &lt;mailto:[email protected]&gt; .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  agent(ex:derek,
-        [prov:type='prov:Person', foaf:givenName='Derek', 
-         foaf:mbox='&lt;mailto:[email protected]&gt;'])
-    </pre>
-   </div>
-   <p>
-    Derek works as part of an organization, Chart Generators Inc, and so the provenance
-    declares that he acts on their behalf. Note that the organization is itself
-    an agent.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:derek prov:actedOnBehalfOf ex:chartgen .
-  ex:chartgen a prov:Agent ;
-              a prov:Organization ;
-              foaf:name "Chart Generators Inc" .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  agent(ex:chartgen,
-        [prov:type='prov:Organization',
-         foaf:name = 'Chart Generators Inc'])
-  actedOnBehalfOf(ex:derek, ex:chartgen, ex:compose)
-    </pre>
-   </div>
-   <p>
-    Finally, there is an explicit statement in the provenance that the chart was
-    attributed to Derek.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:chart1 prov:wasAttributedTo ex:derek .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  wasAttributedTo(ex:chart1, ex:derek)
-    </pre>
-   </div>
-
-   <p>
-    We can extend our graphical depiction to show the agents, association and attribution links.
-   </p>
-   <img src="images/agents.png" alt="Agents added to provenance graph and linked to entities and activities"  width="95%"/>
-  </section>
-
-  <section>
-   <h3>Roles</h3>
-
-   <p>
-    For Betty to understand where the error lies, she needs to have more detailed 
-    information on how entities have been used in and generated 
-    by activities.  Betty has determined that <code>ex:compose</code> used 
-    entities <code>ex:regionList</code> and <code>ex:dataSet1</code>, but she does not 
-    know what function these entities played in the processing.  Betty 
-    also knows that <code>ex:derek</code> was associated with the activities, but she does 
-    not know if Derek was the analyst responsible for determining how the data 
-    should be composed.
-   </p>
-   <p>
-    The above information is described as roles in the provenance. The composition
-    activity involved entities in four roles: the data to be composed (<code>ex:dataToCompose</code>),
-    the regions to aggregate by (<code>ex:regionsToAggregateBy</code>), the
-    resulting composed data (<code>ex:composedData</code>), and the
-    analyst doing the composition (<code>ex:analyst</code>).
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:dataToCompose        a prov:Role .
-  ex:regionsToAggregateBy a prov:Role .
-  ex:composedData         a prov:Role .
-  ex:analyst              a prov:Role .
-    </pre>
-    <p>
-     Examples in the sections above show descriptions of the simple facts that the
-     composition activity used, generated and was enacted by entities/agents.
-     For example, the usage of the data set by the compose activity is expressed
-     as follows.
-    </p>
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose prov:used ex:dataSet1 .
-    </pre>
-    <p>     
-     The
-     provenance can contain more details of exactly how these entities and agents
-     were involved in the activity. 
-     To express this, PROV-O refers to <i>qualified usage</i>, <i>qualified generation</i>, etc.,
-     which are descriptions consisting of several statements about how usage, generation, etc. took place.
-     For example, we may describe the plan followed by an agent in performing an activity, or
-     the time at which an activity generated an entity, both illustrated later.
-     Another example of qualified involvement is the role an entity played in an activity.
-     The descriptions below state
-     that the composition activity (<code>ex:compose</code>) included the usage
-     of the government data set (<code>ex:dataSet1</code>) in the role of the data
-     to be composed (<code>ex:dataToCompose</code>).
-    </p>
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose prov:qualifiedUsage [
-                a prov:Usage ;
-                prov:entity  ex:dataSet1 ;
-                prov:hadRole ex:dataToCompose 
-     ] .
-    </pre>
-   </div>
-   <div class="provn example">
-    <p>
-     In PROV-N, the role is expressed as one of the list of attributes in the used
-     expression, with the attribute name <code>prov:role</code>.
-    </p>
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  used(ex:compose, ex:dataSet1, -, [prov:role='ex:dataToCompose'])
-    </pre>
-   </div>
-   <p>
-    This can then be distinguished from the same activity's usage of the list of
-    regions because the roles played are different.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose prov:qualifiedUsage [
-                a prov:Usage ;
-                prov:entity  ex:regionList ;
-                prov:hadRole ex:regionsToAggregateBy
-     ] .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  used(ex:compose, ex:regionList, -, [prov:role='ex:regionsToAggregateBy'])
-    </pre>
-   </div>
-   <p>
-    Similarly, the provenance includes descriptions that the same activity was
-    enacted in a particular way by Derek, so it indicates that he had the role of 
-    <code>ex:analyst</code>, and that the entity <code>ex:composition</code> took the role of the composed
-    data in what the activity generated:
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:compose prov:qualifiedAssociation [
-                a  prov:Association ;
-                prov:agent    ex:derek ;
-                prov:hadRole  ex:analyst
-  ] .
-  ex:composition prov:qualifiedGeneration [
-                     a prov:Generation ;
-                     prov:activity  ex:compose ;
-                     prov:hadRole   ex:composedData
-  ] .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  wasAssociatedWith(ex:compose, ex:derek, -, [prov:role='ex:analyst'])
-  wasGeneratedBy(ex:composition, ex:compose, -, [prov:role='ex:composedData'])
-    </pre>
-   </div>
-   <p>
-    Depicting the above visually, we have the following.
-   </p>
-   <img src="images/roles.png" alt="Provenance graph annotated with roles played by entities and agents"/>
-  </section>
-
-  <section>
-   <h3>Derivation and Revision</h3>
-
-   <p>
-    After looking at the detail of the compilation activity, there appears
-    to be nothing wrong, so Betty concludes the error is in the government dataset. 
-    She looks at the dataset <code>ex:dataSet1</code>, 
-    and sees that it is missing data from one of the zipcodes in the area.  She contacts
-    the government agency, and a new version of GovData is created, declared to be the
-    next revision of the data. The provenance of this new dataset,
-    <code>ex:dataSet2</code>, states that it is a revision of the
-    old data set, <code>ex:dataSet1</code>.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:dataSet2 a prov:Entity ;
-              prov:wasRevisionOf ex:dataSet1 .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  entity(ex:dataSet2)
-  wasDerivedFrom(ex:dataSet2, ex:dataSet1, [prov:type='prov:Revision'])
-    </pre>
-   </div>
-   <p>
-    Derek notices that there is a new dataset available and creates a new chart based on the revised data, 
-    using another compilation activity. Betty checks the article again at a
-    later point, and wants to know if it is based on the old or new GovData.
-    She sees a new description stating that the new chart is derived from the new dataset.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:chart2 a prov:Entity ;
-            prov:wasDerivedFrom ex:dataSet2 .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  wasDerivedFrom(ex:chart2, ex:dataSet2)
-    </pre>
-   </div>
-   <p>and that the new chart is a revision of the original one:
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:chart2 a prov:Entity ;
-            prov:wasRevisionOf ex:chart1 .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  entity(ex:chart2)
-  wasDerivedFrom(ex:chart2, ex:chart1, [prov:type='prov:Revision'])
-    </pre>
-   </div>
-   <p>
-    Derivation and revision are connections between entities, and so depicted
-    with arrows in our visualization.
-   </p>
-   <img src="images/derivation.png" alt="Derivation and revision links between entities"/>
-  </section>
-
-  <section>
-   <h3>Plans</h3>
-
-   <p>
-    Betty then wishes to know whether the new data set correctly addresses
-    the error that existed before. The provenance of the new dataset,
-    <code>ex:dataSet2</code>, describes not only who performed the corrections,
-    Edith, but also what instructions she followed in doing so (in PROV terms, the plan).
-    First, the correction activity (<code>ex:correct</code>), the person who corrected
-    it, Edith (<code>ex:edith</code>), and the correction instructions (<code>ex:instructions</code>)
-    are described.
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:correct      a prov:Activity .
-  ex:edith        a prov:Agent, prov:Person .
-  ex:instructions a prov:Plan .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  activity(ex:correct)
-  agent(ex:edith, [prov:type='prov:Person'])
-  entity(ex:instructions)
-    </pre>
-   </div>
-   <div class="turtle example">
-    <p>
-     The connection between them is expressed in PROV-O using a qualified association giving details of
-     how Edith was associated with the correction activity,
-     including that she followed the above correction instructions.
-    </p>
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:correct prov:qualifiedAssociation [
-                 a Association ;
-                 prov:agent   ex:edith ;
-                 prov:hadPlan ex:instructions
-  ] .
-  ex:dataSet2 prov:wasGeneratedBy ex:correct .
-    </pre>
-   </div>
-   <div class="provn example">
-    <p>
-     In PROV-N, the plan is an optional parameter to wasAssociatedWith descriptions.
-    </p>
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  wasAssociatedWith(ex:correct, ex:edith, ex:instructions)
-  wasGeneratedBy(ex:dataSet2, ex:correct, -)
-    </pre>
-   </div>
-   <p>
-    Plans are additional information about the connection from an activity to
-    an agent, and so, in our visualization, connect to the link between them.
-   </p>
-   <img src="images/plans.png" alt="Annotaion of example provenance graph with plan followed"/>
-  </section>
-
-  <section>
-   <h3>Time</h3>
-
-   <p>
-    The government agency that produced GovData is concerned to know how long
-    the incorrect chart was in circulation before the corrected chart was created.
-    That is, they wish to compare the times at which the original and the corrected
-    charts were generated. The snippet below shows that the second chart
-    was generated roughly a month after the first.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:chart1 prov:generatedAtTime "2012-03-02T10:30:00"^^xsd:dateTime .
-  ex:chart2 prov:generatedAtTime "2012-04-01T15:21:00"^^xsd:dateTime .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  wasGeneratedBy(ex:chart1, ex:compile,  2012-03-02T10:30:00)
-  wasGeneratedBy(ex:chart2, ex:compile2, 2012-04-01T15:21:00)
-    </pre>
-   </div>
-
-   <p>
-    To ensure their procedures are efficient, the agency also wish to know how long the
-    corrections took once the error was discovered. That is, they wish to know the
-    start and end times of the correction activity (<code>ex:correct</code>).
-    These details are expressed as follows, showing that the corrections took a
-    little over a day.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:correct prov:startedAtTime "2012-03-31T09:21:00"^^xsd:dateTime ;
-             prov:endedAtTime   "2012-04-01T15:21:00"^^xsd:dateTime .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  activity(ex:correct, 2012-03-31T09:21:00, 2012-04-01T15:21:00)
-    </pre>
-   </div>
-   <p>
-    Time is visualized as additional information regarding activities or the
-    links between activities and entities or agents.
-   </p>
-   <img src="images/time.png" alt="Annotation of provenance graph with example timestamps" width="95%"/>
-  </section>
-
-  <section>
-   <h3>Alternate Entities and Specialization</h3>
-
-   <p>
-    Before noticing anything wrong with the government data, Betty had already
-    posted a blog entry about the article. The blog entry had its own published
-    provenance, stating that it quoted some text from the article.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:blogEntry a prov:Entity ;
-               prov:wasQuotedFrom ex:article .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  entity(ex:blogEntry)
-  wasDerivedFrom(ex:blogEntry, ex:article, [prov:type='prov:Quotation'])
-    </pre>
-   </div>
-   <p>
-    The newspaper, from past experience, anticipated that there could be revisions
-    to the article, and so created identifiers for both the article in general
-    (<code>ex:article</code>) as a URI that got redirected to the first version of the article (<code>ex:articleV1</code>),
-    allowing both to be referred to as entities in provenance data. 
-    In the provenance records, the newspaper describes the connection between the two: that
-    the first version of the article is a specialization of the article in general.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:articleV1 a prov:Entity ;
-               prov:specializationOf ex:article .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  entity(ex:articleV1)
-  specializationOf(ex:articleV1, ex:article)
-    </pre>
-   </div>
-   <p>
-    Later, after the data set is corrected and the new chart generated, a new version
-    of the article is created, <code>ex:articleV2</code>, with its own URI where the article
-    is redirected to.  To ensure that those
-    consulting the provenance of <code>ex:articleV2</code> understand that it
-    is connected with the provenance of <code>ex:article</code> and <code>ex:articleV1</code>,
-    the newspaper describes how these entities are related.
-   </p>
-   <div class="turtle example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>Turtle Example</b></span></div>
-    <pre>
-  ex:articleV2 prov:specializationOf ex:article .
-  ex:articleV2 prov:alternateOf      ex:articleV1 .
-    </pre>
-   </div>
-   <div class="provn example">
-    <div class="exampleheader">
-     <span class="exampleheader"><b>PROV-N Example</b></span></div>
-    <pre>
-  specializationOf(ex:articleV2, ex:article)
-  alternateOf(ex:articleV2, ex:articleV1)
-    </pre>
-   </div>
-   <p>
-    Note that above we could have also
-    stated that <code>ex:articleV2</code> was a revision of <code>ex:articleV1</code>,
-    as we did between <code>ex:chart2</code> and <code>ex:chart1</code>,
-    which would describe more concretely how the alternate entities are related.
-    Specialization and alternate relations connect entities, and so are visualized
-    as links between them.
-   </p>
-   <img src="images/specialization.png" alt="Specialization and alternate links between entities"/>
-  </section>
-
-  <section>
-   <h3>Complete PROV data</h3>
-   <p>
-    We visualize the whole example below.
-   </p>
-   <img src="images/everything.png" alt="Provenance graph for whole example" width="95%"/>
-  </section>
- </section>
-
- <section class="appendix">
-  <h2>Acknowledgements</h2>
-  <p>
-   The Provenance Working Group members.
-  </p>
- </section>
-
- <section class="appendix"> 
-  <h2>Changes Since Second Public Working Draft</h2> 
-  <ul>
-   <li>Added selection between Turtle and PROV-N examples with supporting text.</li>
-   <li>Removed PROV-N appendix.</li>
-   <li>Removed reference to accounts, using bundles instead.</li>
-   <li>Scaled the width of wide figures to aid printing.</li>
-   <li>Used generatedAtTime rather than qualified PROV-O.</li>
-   <li>Many clarifications and improvements throughout the text.</li>
-  </ul>
- </section>
-
-</body></html>