On 4/14/17, 4:53 PM, "Stephen Stead" <[email protected]> wrote:
Robert
1] Of course the superclass constrains the contents of a subclass.
4] The distinctions are Very clear and it would be a logical inconsistency
to move E78 so that it was a sub-class either directly or indirectly of only
E22 because then you could not have features in a collection. Which would be
strange.
The superclass constrains the functionality and semantics of the subclass, but
not its related resources.
It’s perfectly possible to say:
_:collection a E78_Curated_Holding ;
P46_is_composed_of _:1, _:2, _:3 .
_:1 a ManMadeObject .
_:2 a Feature .
_:3 a PhysicalObject .
Those statements would hold regardless of the super-classes of E78, so long as
E18 is an ancestor (to get P46).
(And even then you could still do that outside of OWL, as the use of P46 would
simply imply that the E78 is an E18 as well)
So I’m afraid that I still disagree. The change that would make features not
able to be part of a Collection would be to change _its_ superclass to not be
E18.
2] I disagree with your contention that E19 contains all aggregates. It
contains a subset of all aggregates; that is those that are "made for
functional purposes".
Okay, I elided “for functional purposes” but unless collections are not “made
for functional purposes” then the point stands.
And if there are aggregations of things that are made for no functional purpose
at all, I question whether Issue 270 is even remotely valid. A Hoard has no
*function* in and of itself. It’s just an aggregation of objects. It’s not a
Collection, so if it’s not a E19 … what is it? Ditto an Art Dealer’s stock.
Ditto the set of objects in an Auction Lot. Ditto the set of objects in an
archive. Ditto …
If it is impossible to describe these extremely common things in the cultural
heritage sector using CRM, there is a very simple solution that involves not
using CRM, but I would like to be 110% certain of that before invoking that
nuclear option.
3] E78s are not just aggregations of objects they are aggregations of
instances of E18 Physical Thing which includes things other than objects like
features.
Sure. But so are E19s according to the ontology. This is completely legitimate
as E25, E26 and E27 are all descendants of E18:
_:SetOfFeatures a E19_PhysicalObject ;
P46_is_composed_of _:1, _:2, _:3 .
_:1 a E26_Physical_Feature .
_:2 a E27_Site .
_:3 a E25_Man-Made_Feature .
Stephen Stead
Tel +44 20 8668 3075
Mob +44 7802 755 013
E-mail [email protected]
LinkedIn Profile http://uk.linkedin.com/in/steads
-----Original Message-----
From: Robert Sanderson [mailto:[email protected]]
Sent: 14 April 2017 21:17
To: [email protected]; 'Christian-Emil Smith Ore'
<[email protected]>; 'crm-sig' <[email protected]>
Subject: Re: [Crm-sig] E78 Collection vs E19 Physical Object
Hi Stephen,
I don’t follow why the class of the collection affects what can be
collected? A curated collection of features is not itself a feature, and hence
could be an E22. Could you explain your objection further please? Features are
a sub-class of E18, which can be included into either an E78 or E19, as the
predicate is defined with E18 as the domain which is the ancestor of both.
It would be helpful to clarify the distinction between the two classes:
“This class comprises aggregations of instances of E18 Physical Thing” … as
P46 comes from E18, that’s no problem, as E19 is a sub-class of E18.
“The class also includes *all* aggregates of objects” … in all
practicality, this is exactly the same as E78 as P46’s domain and range are E18.
The documentation says:
All aggregations of objects are E19s.
E78s are aggregations of objects.
E78s are not E19s.
I contend there is a logical inconsistency.
Rob
On 4/14/17, 12:46 PM, "Stephen Stead" <[email protected]> wrote:
E78 is intended to allow a curated collection of features not just of
objects and so does not belong as a sub-class of E22.
I am unclear what the Identity, Unity, Existence and Substance criteria
for a "Set" would be and thus find it difficult to conceive of it being a class.
The long list of things that do not fit under E78 suggests that
criteria are actually a "real" partition of the world that is in our scope.
Many of the things that do not fit are either out-of-scope or are not curated
collections or both.
In the case that there is something that is both an instance of E19 and
E78 then multiple instantiation is the solution not tinkering with the class
definitions.
CEO's desire to replace 'assembled' might be tackled with "grouped"
instead. Not sure, still thinking about it.
Stephen Stead
Tel +44 20 8668 3075
Mob +44 7802 755 013
E-mail [email protected]
LinkedIn Profile http://uk.linkedin.com/in/steads
-----Original Message-----
From: Crm-sig [mailto:[email protected]] On Behalf Of Robert
Sanderson
Sent: 14 April 2017 17:36
To: Christian-Emil Smith Ore <[email protected]>; 'crm-sig'
<[email protected]>
Subject: Re: [Crm-sig] E78 Collection vs E19 Physical Object
Dear Christian-Emil, all,
Yes – I’ve followed 270 over its evolution. To me, there are still two
issues not addressed in 270:
1. E78 curated aggregation is not a descendant of the class used for
general aggregations E19.
2. There are a lot of aggregations that do not fit into the scope
notes.
For 1, if it’s accepted as an issue to be solved, then I propose that
E78 become a sub-class of E22 Man Made Object
Currently E78 is a sub-class of only E24.
E22 is a sub-class of both E19 and E24.
Thus the simplest change to have E78 descend also from E19 is to move
E78 to be a child of the existing E22.
Or, more comprehensively, introduce a new class below E19 for Sets, and
move P57 to it, then make E78 a child of the new class and of E24.
If P57 is intended to be used for more than membership, then it should
instead be on E18 along with P46.
For 2, I would propose to remove the following text from E78’s scope
note:
“over time for a specific purpose and audience, and according to a
particular collection development plan.”
An art dealer’s stock is assembled for a specific purpose, I think
curated is appropriate, arguably for the audience of art buyers (which seems a
bit meaningless), but unless you count “buy low, sell high” as a collection
development plan, it does not fit under E78. Ditto Auction lots, consignments,
personal collections, and so forth. Personal collections probably fail the
specific purpose clause, unless “my amusement” counts as a purpose.
That said, if issue 1 is solved, I would also be happy with simply
changing the reference to E19 in the E78 note:
From: This is because they form wholes either because they are
physically bound together or because they are kept together for their
functionality.
To: This is because they do not have collection plans that are
followed over time.
A Collection could be physically bound together. A Collection could be
kept together for its functionality. The importance is the management of it,
not the physical composition or subjective reason for the particular grouping.
Rob
On 4/14/17, 4:39 AM, "Christian-Emil Smith Ore" <[email protected]>
wrote:
Hi Robert,
The E78 Collection changed name (which of course does not mean
anything since the name of a class is just a label and the definition is given
by the scope note.) to E78 Curated Holding a year ago (issue 270 resolved in
Prato February 2016). The CRM 6.2.2 is not completely updated - unfortunately.
The crucial point is: Can an instance of E78 Curated Holding
consist of stuff (to use the old term) that is not moved and cannot be moved.
The first sentence of the scope note indicates that a curated holding consists
of things that are assembled and thus moved (demonstrating that they are
physical objects).
"This class comprises aggregations of instances of E18 Physical
Thing that are assembled..."
If this is the case, one may argue that any assembly of physical
objects is in itself a physical object. On the other hand there may well be a
open air museum where the collection consists of log houses placed in different
locations (say, 1 kilometer apart) but curated collectively. It may be somewhat
artificial to model such a collection as a single physical object.
However, I agree that the word 'assembled' may cause confusions.
If you agree that my collection of log houses should not be modeled as a single
physical object, could you suggest a better formulation in the scope note?
Best
Christian-Emil
********************************************
E78 Curated Holding
Subclass of: E24 Physical Man-Made Thing
Scope note: This class comprises aggregations of instances of E18
Physical Thing that are assembled and maintained (“curated” and “preserved,” in
museological terminology) by one or more instances of E39 Actor over time for a
specific purpose and audience, and according to a particular collection
development plan. Typical instances of curated holdings are museum
collections, archives, library holdings and digital libraries. A digital
library is regarded as an instance of E18 Physical Thing because it requires
keeping physical carriers of the electronic content.
Items may be added or removed from an E78 Curated Holding in
pursuit of this plan. This class should not be confused with the E39 Actor
maintaining the E78 Curated Holding often referred to with the name of the E78
Curated Holding (e.g. “The Wallace Collection decided…”).
Collective objects in the general sense, like a tomb full of gifts,
a folder with stamps or a set of chessmen, should be documented as instances of
E19 Physical Object, and not as instances of E78 Curated Holding. This is
because they form wholes either because they are physically bound together or
because they are kept together for their functionality.
Examples:
the John Clayton Herbarium
the Wallace Collection
Mikael Heggelund Foslie’s coralline red algae Herbarium at
Museum of Natural History and Archaeology, Trondheim, Norway
**********************************************
E19 Physical Object
Subclass of: E18 Physical Thing
Superclass of: E20 Biological Object
E22 Man-Made Object
Scope note: This class comprises items of a material nature that
are units for documentation and have physical boundaries that separate them
completely in an objective way from other objects.
The class also includes all aggregates of objects made for
functional purposes of whatever kind, independent of physical coherence, such
as a set of chessmen. Typically, instances of E19 Physical Object can be moved
(if not too heavy).
In some contexts, such objects, except for aggregates, are also
called “bona fide objects” (Smith & Varzi, 2000, pp.401-420), i.e. naturally
defined objects.
The decision as to what is documented as a complete item, rather
than by its parts or components, may be a purely administrative decision or may
be a result of the order in which the item was acquired.
Examples:
John Smith
Aphrodite of Milos
the Palace of Knossos
the Cullinan Diamond
Apollo 13 at the time of launch
*****************************************************
________________________________________
From: Crm-sig <[email protected]> on behalf of Robert
Sanderson <[email protected]>
Sent: 14 April 2017 04:20
To: 'crm-sig'
Subject: [Crm-sig] E78 Collection vs E19 Physical Object
Dear all,
A question completely unrelated to states, I promise (
E78 Collection is described as: “This class comprises aggregations
of instances of E18 Physical Thing that are assembled and maintained …”
And E19 Physical Object’s scope note says: “The class also
includes *all* aggregates of objects made for functional purposes of *whatever
kind*, …”
(emphasis added)
However E78 is not a descendant of E19 … they are both independent
descendants of E18.
So every E78 Collection must also be, explicitly, an E19 Physical
Object? This seems like a bug in the class hierarchy?
And regardless of the hierarchy, if there is a set of objects that
are not “physically bound together or […] kept together for their
functionality” (hence not E19), but do not have a “particular collection
development plan” (hence not E78 either) … how should they be modeled?
Examples include auction lots, the set of objects that are looked after by an
art dealer (but without a development plan), and similar.
Many thanks!
Rob
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