issue 331 and 342
authorLuc Moreau <l.moreau@ecs.soton.ac.uk>
Thu, 12 Apr 2012 15:50:56 +0100
changeset 2276 d13170bebb69
parent 2273 ac1c7030a736
child 2277 d14a770c259a
issue 331 and 342
model/comments/issue-331-Tim.txt
model/glossary.html
model/glossary.js
model/prov-dm.html
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/model/comments/issue-331-Tim.txt	Thu Apr 12 15:50:56 2012 +0100
@@ -0,0 +1,700 @@
+  > DM editors,
+  > 
+  > Please find here:
+  > 
+  > * Response to your specific questions, then 
+  > * Comments that follow the document.
+  > 
+  > Regards,
+  > Tim
+  > 
+  > ===================
+  > 
+  > Editor's questions:
+  > 
+  >     *  Can the document be released as a next public working draft? If no, what are the blocking issues? 
+  > 
+  > Yes-ish. Releasing the draft with the current state of
+  > specializationOf concerns me. I would be willing to let the draft go
+  > public, but would much prefer another pass here.
+  > 
+  >     * Is the structure of the document approved? 
+  > 
+  > Yes. It flows naturally.
+  > 
+  >     * Can the short name of the document be confirmed (in particular,
+  >       for prov-n, prov-dm-constraints, since request needs to be sent
+  >       for publication)?
+  > 
+  > yes.
+  > 
+  > 
+  > 
+  >     * If a reviewer raised some issues (closed pending review), can they be closed? 
+  > 
+  > If the traditional request mechanism is used and provides the raiser
+  > one more check, yes.
+  > 
+  > 
+  > 
+  > 
+  >     * Can all concept definitions be confirmed? Specifically,
+  >           o consider ISSUE-337 on agents
+  > 
+  > (yes) The treatment of agent is fine. The fact that it is an entity
+  > seems unnatural, given that it is one of the principal concepts it
+  > should not be stuck under Entity. One can make an agent an entity at
+  > any time, so we are not losing anything by keeping Agent, Entity, and
+  > Activity at the top level.
+  > 
+  >     *
+  > 
+  > 
+  >           o consider ISSUE-223 on entities 
+  > 
+  > (yes) "An entity is a thing one wants to provide provenance for. For
+  > the purpose of this specification, things can be physical, digital,
+  > conceptual, or otherwise; things may be real or imaginary." is
+  > fine. In particular "wants to provide provenance for" is
+  > important. The breadth of entity is conveyed by the end of the
+  > definition. Entities contrast with Activities, which is another
+  > important aspect.
+  > 
+  > 
+  > NO, specializationOf needs help. It is NOT owl:sameAs, but seems to
+  > always drift back to something TOO close to it. "Things and Refer"
+  > should not appear in the definition. I wish the WG would stop fighting
+  > over competing detailed definitions and leave it in its abstract form
+  > for general use (and extension).
+  > 
+  > 
+  > 
+  > 
+  > 
+  > 
+  > 
+  > 
+  > ==========================
+  > <> dcterms:subject <http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html> .
+  > 
+  > General comments:
+  > 
+  > 1)
+  > "actities" typo
+
+Done
+  > 
+  > 
+  > 2)
+  > The summary "component 4: properties to link entities that refer to a same thing;" seems misleading.
+  > (Though, with the flurry of recent discussions on this, it's not clear what a better summary is)
+  > 
+  > 3)
+  > odd phrasing: "which are allows users"
+
+Fixed
+  > 
+  > 4)
+  > typo: "completion of the the act of producing"
+  > 
+
+Fixed
+
+  > 5)
+  > Generation defintiion seems odd when split over two sentences:
+  > "This entity becomes available for usage after this generation. This entity did not exist before generation."
+  > ->
+  > "This entity did not exist before generation and becomes available for usage after this generation."
+  > 
+  > 6)
+  > The following could benefit from a rephrasing:
+  > "A Web site and service selling books on the Web and the company hosting them are software agents and organizations, respectively."
+  > 
+  > 7)
+  > Section 2.4 seems to be asymmetric.
+  > Attribution has one definition and example. (thus does not get as much or adequate attention compared to association)
+  > Association has two leading paragraphs (which at first reading
+  >     seem like they should be supporting "attribution" and not
+  >     introducing the subsequent "attribution")
+  > 
+  > 8)
+  > Should tables and figures be numbered?
+  > "Table (Mapping of Provenance concepts to types and relations in PROV-DM)"
+  > 
+  > 9)
+  > The following seems to be out of place, or does not link to the fulfillment of its promise:
+  > "When examining PROV-DM in details, some relations, while involving two primary elements, are shown to be nary."
+  > * Is it "in detail"?
+  > * suggest to add link to where these "detail" and "nary" are discussed later in the document.
+  > 
+  > 10)
+  > It seems asymmetric that "wasInformedBy" is not part of the diagram
+  > http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html#
+  > 
+  > The diagram answers how entities can relate to entities, and agents to
+  > agents, but activities seem less primary without having their own
+  > intra-relation.  (This, noting that the diagram "is not intended to be
+  > complete.")  Communication occurs throughout the publication example,
+  > so it could be added.
+  > 
+  > 
+  > 11)
+  > The final paragraph in section 2.5 tries to tie things together, but it does not do so clearly.
+  > """
+  > 
+  > Figure overview-types-and-relations is not intended to be complete. It
+  > only illustrates types and relations from Section starting-points and
+  > exploited in the example discussed in the next section. They will then
+  > be explained in detail in Section data-model-components. The third
+  > column of Table (Mapping of Provenance concepts to types and relations
+  > in PROV-DM) lists names that are part of a textual notation to write
+  > instances of the PROV-DM data model. This notation, referred to as the
+  > PROV-N notation, is outlined in the next section.  """
+  > 
+  > * for the intended purpose, "Section starting-points" is _this_ section (and not some other that needs to be hunted down).
+
+  > * "example discussed in the next section" provides a relative reference that could be more informative. Perhaps "following section" can help.
+  > * "They will then be explained" -> "The starting points will be explained"
+  > * Not having numbers on the sections makes it difficult to infer the organization.
+  > * The point about the third column in the table means nothing to me. Why do I care? Is this useful in PROV-N land? It's not mentioned explicitly until the following sentence (which is where it is re-introduced unnecessarily).
+  > 
+  > 
+  > 12)
+  > Expressions are not identified, but the following could be interpreted as such:
+  > "Most expressions have an identifier which always occur in first position"
+  > * suggest to rephrase so that the expression mentions (not has) an identifier.
+  > 
+  >  
+  > 13)
+  > Not sure semicolon is appropriate here:
+  > "; we then provide attribution"
+  > 
+  > 
+  > 14)
+  > "must also preceded by" missing a "be"?
+  > 
+  > 15)
+  > Odd phrasing: "(some of which locating archived email messages"
+  > 
+  > 16)
+  > suggest removing "agent" from "were published by the WWW Consortium agent"
+  > -- it sounds like some software did it.
+  > 
+  > 
+  > 17)
+  > Collective confusion in example
+  > * What is prefix "ar2" and "ar3" and "ar1"?
+  > * All of the numbers in the names make it hard to keep track of things (e.g. ar1:0004?)
+  > * 404: "Full details of the provenance record can be found here." -> http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/examples/w3c-publication1.pn
+  > * more unrecognizable prefixes: pr:RecsWD
+  > * "it happens that all entities were already Web resources, with
+  >   readily available URIs, which we used" - this seems only to be true
+  >   for the two reports and nothing else.
+  > 
+  > * 404: "Full details of the provenance record can be found here" ->
+  >   http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/examples/w3c-publication3.pn
+  > 
+  > 18)
+  > This phrase seems to have the opposite affect of its intent:
+  > "its details differ from the author's perspective" 
+  > * Perhaps "its details differ according to the asserting author"
+  > 
+  > 19)
+  > Perhaps switch the two accounts in the example section. The second one is much smaller (and actually happens first).
+  > This could help readability.
+  > 
+  > 20)
+  > Before section 4, the distinction between concepts and types/relations was made (to the extend of showing their mapping).
+  > Yet section 4 (titled types and relations) says "PROV-DM concepts are structured according to six components that are introduced in this section"
+  > * suggest to replace "concepts" with types and relations.
+  > * suggest to be precise about the relation between "concepts" and "types and relations" and to use then consistently.
+  > 
+  > 
+  > 21)
+  > Beginning of section 4:
+  > "operations related to collections."
+  > * suggest to rephrase this with examples like in component 1; mentioning insertion and removal.
+  > 
+  > 
+  > 22)
+  > http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html#prov-dm-concepts-and-relations
+  > * suggest adding a textual indicator for the component (to readability, and to avoid potential accessibility issues for visually impaired).
+  > * Also, the color code does not exist on the same page (one must scroll up to see it).
+  > 
+  > 23)
+  > Second column for Collection seems odd in 
+  > http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html#prov-dm-concepts-and-relations
+  > 
+  > 24)
+  > "The attributes ex:version is" -> "The attribute ex:version is"
+  > 
+  > 
+  > 25)
+  > Why is:
+  > """
+  > 
+  >   wasGeneratedBy(e1,a1, 2001-10-26T21:32:52, [ex:port="p1"])
+  >   wasGeneratedBy(e2,a1, 2001-10-26T10:00:00, [ex:port="p2"])
+  > 
+  > """
+  > not:
+  > 
+  >   wasGeneratedBy(-,e1,a1, 2001-10-26T21:32:52, [ex:port="p1"])
+  >   wasGeneratedBy(-,e2,a1, 2001-10-26T10:00:00, [ex:port="p2"])
+  > 
+  > Is there an exception to the "- rule"?
+  > 
+  > 
+  > 26)
+  > 
+  > What started in this phrase: "Any usage or generation involving an activity follows its start."
+  > 
+  > * suggest rephrasing to make it clear that the activity is the thing starting.
+  > 
+  > * perhaps "Any usage or generation by an activity must follow the activity's start"
+  > 
+  > * similar comment for definition of End
+  > 
+  > 
+  > 27)
+  > 
+  > For Start's example:
+  > 
+  > "if the activity happens to consume the message content" could safely be removed for clarity. (the "regarded as an input" covers it more clearly)
+
+  > 
+  > 28)
+  > 
+  > Should  "wasAttributedTo(ex:foot_race,ex:DarthVader)" be "wasAttributedTo(ex:bang,ex:DarthVader)" ?
+  > 
+  > 
+  > 29)
+  > 
+  > Regarding: "Consider two long running services, which we represent by activities  s1 and s2."
+  > 
+  > It seems odd that services are considered activities. Should they not be agents that perform more granular activities?
+  > 
+
+  > * perhaps this example could be replaced to avoid yet another computer
+  >   example: the "fine paying; check writing; mailing" activity was
+  >   informed by the "traffic stop" activity. The implicit entity is a
+  >   traffic ticket that had a notice of fine, amount, and payment
+  >   mailing address.
+
+
+  > 
+  > 30)
+  > 
+  > Start by Activity continues to be an outlier in this model. It's just a simple case of communication. 
+  > 
+  > Recommend to drop start by activity.
+  > 
+  > https://www.w3.org/2011/prov/track/issues/340
+  > 
+  > 
+  > 
+  > 31)
+  > 
+  > Is http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html#figure-component2
+  > 
+  >
+  > 
+  >  legitimate UML that can be interpreted by anybody outside of DM? Why
+  >  isn't wasAssociatedWith class relating to Activity and Agent (like an
+  >  ERD would do)?
+  > 
+  > 
+  > 
+  > 32)
+  > 
+  > "are responsible in some way for the activity to take place"
+  > 
+  > -> "are responsible in some way for the activity that took take place"
+  > 
+  > 
+  > 
+  > 33)
+  > 
+  > The "length > 1" connotation here concerns me:
+  > 
+  > "id:  an optional identifier for the responsibility chain;"
+  > 
+  > It seems to suggest that multiple one-step responsibilities should point to their aggregation, which I don't believe is the case.
+  > 
+  > * suggest to rephrase to "responsibility link [between subordinate and responsible]"
+  > 
+  > 
+  > 
+  > 
+  > 34)
+  > 
+  > suggest "attribute-value pairs that describe the modalities of this relation." 
+  > 
+  > -> "attribute-value pairs that describe the modalities of this responsibility link." 
+  > 
+  > 
+  > 35)
+  > 
+  > "and a funder agents" -> "and a funder agent"
+  > 
+  > "has an contractual agreement" -> "has a contractual agreement"
+  > 
+  > 
+  > 36)
+  > 
+  > should responsibility example include:
+  > 
+  > wasAssociatedWith(a,ag3) ?
+  > 
+  > 
+  > 
+  > 
+  > 37)
+  > 
+  > section 4.3:
+  > 
+  > "and subtypes of derivations" -> "subtypes of derivations"
+  > 
+  > 
+  > 
+  > 
+  > 36)
+  > 
+  > Similar to previous, is the binary augmentation shown in
+  > 
+  > http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html#figure-component3
+  > 
+  > a convention known by anybody? It is very difficult to interpret.
+  > 
+  > 
+  > 
+  > 37) 4.3.1
+  > 
+  > The "build up" discussed for adding details about derivation is very nice.
+  > 
+  > 
+  > 
+  > 38)
+  > 
+  > It is difficult to follow 
+  > 
+  > wasDerivedFrom(e2, e1, a, g2, u1)
+  > wasGeneratedBy(g2, e2, a, -)
+  > used(u1, a, e1, -)
+  > 
+  > 
+  > and the paragraph. Perhaps a simple diagram would help follow. (but then this would be inconsistent with other definitions…)
+  > 
+  > 
+  > 
+  > 
+  > 
+  > 39)
+  > 4.3.2
+  > "responsibility: an optional identifier (ag) for the agent who approved the newer entity as a variant of the older;"
+  > 
+  > ^^^ this seems more appropriately modeled as an account, not stuck as part of the underlying model.
+  > 
+  > Revision should "just be", and if one wants to know who says "it just is", we should use accounts to answer.
+  > 
+  > 
+  > The same experience that we used to remove "agent asserting an account" from "account" should be reapplied to this parameter as well.
+  > 
+  > https://www.w3.org/2011/prov/track/issues/341
+  > 
+  > 
+  > 
+  > 
+  > 40)
+  > 
+  > Glad to see the "all" in "A quotation  is the repeat of (some or all of) an entity"
+  > 
+  > 
+  > 
+  > 
+  > 41)  
+  > 
+  > The phrases:
+  > 
+  > "Quotation is a particular case of  derivation in which"
+  > 
+  > and
+  > 
+  > "An original source relation is a particular case of derivation 
+  > that"
+  > 
+  >  are very instructive.
+  > 
+  > 
+  > but this is not done for Revision.
+  > 
+  > * recommend to add this kind of phrase to revision section.
+  > 
+  > 
+  > 
+  > 42) (Thanks for all the fish…)
+  > 
+
+  > "Let us consider the current section dm:term-original-source,"
+  >     seems to describe the concrete form, when in fact you're talking
+  >     about the notions described by the section.
+  > 
+  > * suggest to rephrase to something like "Let us consider the concept described in the current section"
+  > 
+  > 
+  > 
+  > 43)
+  > 
+  > "and the Google page go:credit-where-credit-is-due.html, where the notion was originally described."
+  > 
+  > suggest to += "(to the knowledge of the authors)"
+  > 
+  > 
+  > 
+  > 44)
+  > 
+  > should "Derivation and association are particular cases of  traceability."
+  > 
+  > be "Derivation and _attribution_ are particular cases of  traceability." ?
+  > 
+  > 
+  > 
+  > 45)
+  > 
+  > "w3:Consortium or to
+  > pr:rec-advance." -" w3:Consortium _and_ to pr:rec-advance."
+  > 
+  > 
+  > 
+  > 46)
+  > 
+  > "Wherever two people describe the provenance of a same thing, 
+  > one cannot expect them to coordinate and agree on the identifiers to use to denote that thing."
+  > 
+  > * we are nose diving back to owl:sameAs with this ^^
+  > 
+  > * The example is reasonable (date-specific URI versus non)
+  > 
+  > 
+  > 
+  > 47)
+  > 
+  > "To allow for identifiers to be chosen freely and independently by each  user, the PROV data model introduces relations
+  > that allow entities  to be linked together.
+  > The following two relations are introduced for expressing  specialized or alternate entities."
+  > 
+
+  > ^^ this does not convey the "levels of detail" aspect well enough
+  >     - it emphasizes too much on the "choose your own URI" wild west of
+  >     the web.
+  > 
+  > 
+  > 
+  > 48)
+  > 
+  > References and Things should not be involved in defining
+  > specialization. We've just pushed the "Thing vs. Entity" argument into
+  > specialization.
+  > 
+  > "An entity is a specialization
+  >  of another if they refer to some common thing but the former is a more 
+  > constrained entity than the latter. The common thing do not need to be 
+  > identified. "
+  > 
+  > 
+  > 
+  > 49)
+  > 
+  > http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html#figure-component5
+  > 
+  > has old naming "derivation-by-removal" which was renamed to simpler "removal"
+  > 
+  > (or, if it's not "old", I recommend renaming it)
+  > 
+  > Though, I may just be confused on this (qualified vs. unqualified). Perhaps disregard this comment.
+  > 
+  > 
+  > 
+  > 
+  > 50)
+  > 
+  > "and is a generic indexing mechanisms" -> "and is a generic indexing mechanism"
+  > 
+  > 
+  > 
+  > 
+  > 51)
+  > 
+  > "and more (the specification of such specialized structures in terms of key-value pairs is out of the scope of this document)"
+  > 
+  > -> "and more. The specification of such specialized structures in terms of key-value pairs is out of the scope of this document."
+  > 
+  > 
+  > 
+  > 52)
+  > 
+  > suggest mentioning the word "replacement" in the sentence:
+  > 
+  > "Insertion provides an "update semantics" for the keys that are already 
+  > 
+  > present in the collection, as illustrated by the following example. "
+  > 
+  > 
+  > 
+  > 53)
+  > "This is reflected in the constraints listed in Part II." seems to warrant a link.
+  > 
+  > 
+  > 
+  > 
+  > 54)
+  > first example in annotations
+  > 
+  > "The note's identifier and attributes are declared in a separate namespace denoted by prefix ex2."
+  > 
+  > ^^^ This seems to be insinuating some best practice without explaining
+  >  why they are in different namespaces. It can lead to questions that
+  >  each requires a can of worms.
+  > 
+  > The namespace of the attributes should NOT be in the same namespace as the instance.
+  > 
+  > 
+  > 
+  > 55)
+  > second example in annotations
+  > 
+  > ex3:n2 should NOT be in same namespace as ex3:reputation
+  > 
+  > 
+  > 
+  > 56)
+  > 
+  >  I'll point out _again_ that Notes are a bad way to model
+  >     derivations of provenance; that is what accounts are for. If you
+  >     want to use this shortcut in your design - fine. But don't
+  >     advocate the impoverished design in the recommendation itself --
+  >     snuck in via an example.
+  > 
+
+It is not forgotten. It's ISSUE-260.
+
+Simply I had no time to work on it. 
+To address your point, we need an agreed notion of account.
+
+It is unclear to me whether this is equivalent to a derivation of provenance.
+
+Account and notes are on the chair's chopping list.
+
+
+  > 
+  > 
+  > 
+  > 57)
+  > 
+  > "The interpretation of any attribute declared in another namespace is out of scope."
+  > 
+  > ^^ does this refer to attributes mentioned in this document? 
+  > 
+  > 
+  > 
+  > 
+  > 58)
+  > please add links to the appropriate sections for the contexts mentioned in:
+  > 
+
+  > "The attribute prov:role denotes the function of an entity with
+  >     respect to an activity, in the context of a usage, generation,
+  >     association, start, and end"
+  > 
+  > 
+  > 
+  > 
+  > 59)
+  > Please add links to the appropriate sections for the attributes in:
+  > "The PROV-DM namespace declares a set of reserved attributes catering for extensibility: type, role, location."
+  > 
+  > 
+  > 
+  > 
+  > 60)
+  > Please explicitly cite the parts in:
+  > "must preserve the semantics specified in the PROV-DM documents (part 1 to 3)."
+  > 
+  > 
+  > 
+  > 
+  > 61)
+
+  > 
+  > 
+  > This is inaccurate from the AWWW perspective: "One needs to ensure
+  > that provenance descriptions for the latter document remain valid as
+  > denoted resources change."  What may change is the representation
+  > returned when the resource's denotation (i.e., URI) is requested.
+  > This, in turn, may mislead consumers to a referent distinct from that
+  > originally intended by the author of the denotation.  The resource
+  > didn't change, one's interpretation of what was written changes.
+  > 
+  > 
+  > 
+  > 62) typo: "mechanism for blundling up provenance"
+  > 
+  > 
+  > 
+  > 
+  > 63)
+  > awkward wording: "as well as constraint that structurally well-formed descriptions are expected to satisfy."
+  > 
+  > 
+  > 
+  > 
+  > On Mar 29, 2012, at 9:36 AM, Provenance Working Group Issue Tracker wrote:
+  > 
+  > > PROV-ISSUE-331 (review-dm-wd5): issue to collect feedback on prov-dm wd5 [prov-dm]
+  > >
+  > > http://www.w3.org/2011/prov/track/issues/331
+  > >
+  > > Raised by: Luc Moreau
+  > > On product: prov-dm
+  > >
+  > > When sending feedback, please send it under this issue or individual new issues.
+  > >
+  > >
+  > >
+  > >
+  > 
+----------------------------------------------------------------------
+DM editors,
+
+
+On Apr 10, 2012, at 6:26 PM, Timothy Lebo wrote:
+
+> DM editors,
+>
+> Please find here:
+>
+> * Response to your specific questions, then 
+> * Comments that follow the document.
+>
+> Regards,
+> Tim
+>
+> ===================
+>
+> Editor's questions:
+>
+>     *  Can the document be released as a next public working draft? If no, what are the blocking issues? 
+>
+> Yes-ish. Releasing the draft with the current state of specializationOf concerns me. I would be willing to let the draft go public, but would much prefer another pass here.
+
+
+If the definition of specialization changes to the following, I can change my response to a resounding "YES, RELEASE !".
+4.4.1 Specialization
+"An entity is a specialization of another if they describe some common thing but the former is a more constrained entity than the latter. The common thing does not need to be identified."
+
+-Tim
+
+
+
+
+
--- a/model/glossary.html	Thu Apr 12 14:50:38 2012 +0100
+++ b/model/glossary.html	Thu Apr 12 15:50:56 2012 +0100
@@ -17,7 +17,7 @@
 
 <span class="glossary" id="glossary-generation">  
 <dfn id="concept-generation">Generation</dfn> is the completion of production of a new entity by an activity.
- This entity becomes available for usage after this generation. This entity did not exist before generation.
+This entity did not exist before generation and becomes available for usage after this generation.
 </span>
 
 <span class="glossary" id="glossary-usage">  
--- a/model/glossary.js	Thu Apr 12 14:50:38 2012 +0100
+++ b/model/glossary.js	Thu Apr 12 15:50:56 2012 +0100
@@ -3,7 +3,7 @@
 //  with <script src="glossary.js" class="remove"></script>
 //Insert glossary definitions with the following 
 // <div class="glossary-ref" ref="glossary-generation"></div>
-glossary_hg='http://dvcs.w3.org/hg/prov/file/4e1dede485bc/model/glossary.html';
+glossary_hg='http://dvcs.w3.org/hg/prov/file/ac1c7030a736/model/glossary.html';
 glossary_string= 
 ' ' + 
 '<html> ' + 
@@ -24,7 +24,7 @@
 ' ' + 
 '<span class="glossary" id="glossary-generation">   ' + 
 '<dfn id="concept-generation">Generation</dfn> is the completion of production of a new entity by an activity. ' + 
-' This entity becomes available for usage after this generation. This entity did not exist before generation. ' + 
+'This entity did not exist before generation and becomes available for usage after this generation. ' + 
 '</span> ' + 
 ' ' + 
 '<span class="glossary" id="glossary-usage">   ' + 
--- a/model/prov-dm.html	Thu Apr 12 14:50:38 2012 +0100
+++ b/model/prov-dm.html	Thu Apr 12 15:50:56 2012 +0100
@@ -440,7 +440,7 @@
 <h2>Generation, Usage, Derivation</h2>
 
 <p>Activities and entities are associated with each other in two different ways: activities utilize entities and activities  produce entities. The act of utilizing or producing an entity may have a duration.  
- The term 'generation' refers to the completion of the the act of producing; likewise, the term 'usage' refers to the beginning of the act of utilizing entities. Thus, we define the following notions of generation and usage. </p>
+ The term 'generation' refers to the completion of the act of producing; likewise, the term 'usage' refers to the beginning of the act of utilizing entities. Thus, we define the following notions of generation and usage. </p>
 
 <p>
 <div class="glossary-ref" data-ref="glossary-generation"  data-withspan="true">
@@ -2374,7 +2374,7 @@
 
 
 <p>
-The attribute <dfn title="dfn-location"><span class="name">prov:location</span></dfn> is an OPTIONAL attribute of entity and activity.  The value associated with the  attribute <span class="name">prov:location</span> MUST be a PROV-DM <a title="value">Value</a>, expected to denote a location.
+The attribute <dfn title="dfn-location"><span class="name">prov:location</span></dfn> is an OPTIONAL attribute of entity, activity, usage, and generation.  The value associated with the  attribute <span class="name">prov:location</span> MUST be a PROV-DM <a title="value">Value</a>, expected to denote a location.
 </p>
 
 <div class="anexample">