Issue 92: Declare all disjoint classes

Starting Date: 
2002-02-22
Working Group: 
3
Status: 
Done
Closing Date: 
2002-10-22
Old Proposal: 

In Monterey 22/2/2002, the "disjoint with" relationship was decided.

In the sequence, disjointness declarations are required whereever applicable.

I propose the following "disjoint with" relations in the CIDOC CRM. As the CIDOC CRM in general does not constrain multiple instantiation, this construct allows to exclude some obvious cases. The relationship is symmetric and inherited. I.e. if Persistent Item is disjoint with Temporal Entity, all subclasses of Persistent Item are disjoint with all subclasses of Temporal Entity and vice a versa. Therefore, I refer those relationships only once, and top-down. Any other notation would cause great confusion. As we support recall over precision, it would be worse to have one disjoint declaration too much than one too less. We have done without disjopintness declarations long enough. In this sense, the following list is comprehensive, to the degree we could decide without doubts about disjointness.

Assuming: Type isA Conceptual Object, Legal Object isA Stuff

E2 Temporal Entity Disjoint with:
- Persitent Item
- Place
- Dimension
- Time-Span
- Primitive Value

E77 Persistent Item Disjoint with:
- Place
- Dimension
- Time-Span
- Primitive Value

E53 Place Disjoint with:
- Dimension
- Time-Span
- Primitive Value

E54 Dimension Disjoint with:
- Time-Span
- Primitive Value

E52 Time-Span Disjoint with:
- Primitive Value

E39 Actor disjoint with:
- E24 Physical Man-Made Stuff
- E73 Information Object
- E41 Appellation
- E51 Contact Point
- E55 Type

E18 Physical Stuff disjoint with:
- Conceptual Object

E26 Physical Feature disjoint with:
- Physical Object

E55 Type disjoint with:
- Right

E56 Language disjoint with:
- Material
- Measurement Unit

E57 Material disjoint with:
- Measurement Unit

MD 19/6/2002

Current Proposal: 

In Monterey a proposal was accepted to declare all disjoint classes in order to aid comprehnsion of the CRM (See issue 66), and Martin has now produced a draft list of disjoint class declarations.

However, after reviewing Martin's draft list I realized that it was not (nor intended to be) comprehensive, and that it will be a significant and time-consuming intellectual undertaking to produce a fully comprehensive list of all disjoint class declarations. It almost certainly couldn't be done in time for the Copenhagen meeting.

So, we need to ask ourselves whether an incomplete list of disjoint class declarations is sufficiently useful and comprehsible to include in the CRM, or whether we should abandon the idea of disjoint class declararations altogether? In view of the time constraints we are facing, I am proposing the latter -- that we do not include an incomplete list of disjoint class declarations in the CRM.

TG 20/6/2002

Proposal 2 accepted. Issue open until scope notes written. Copenhagen 3/7/2002

Here the scope notes:

E2 Temporal Entity

Subclass of:

CRM Entity

Superclass of:

Condition State
Period

New Scope note:

This is an abstract entity and has no examples. It groups together transient phenomena such as events, states and others, which are limited in time, also called perdurants. It is specialized into Period, which holds on some geographic area, and Condition State, which holds for, on, or over a certain object. Even though Persitent Items (or endurants) have a limited existence in time, because they may be destroyed, lost or forgotten, we regard them as disjoint from Temporal Enties, as their persistent identity allows to relate Temporal Entities in which they participate.

E77 Persistent Item

Subclass of:

CRM Entity

Superclass of:

Stuff
Contact Point
Appellation
Actor

New Scope note:

E77 Persistent Item encompasses (and thereby isolates) entities which share two attributes: having the potential to exist over a period of time, and having persistent identity during this period of existence. These attributes are intended to apply to both concrete objects, whether animate or inanimate and to ideas or concepts. Hypothetical or imaginary objects fall within this category insofar as they can be considered as conceptual objects i.e. E77 Persistent Item is not intended to be restricted to physical existence. Persistent Items are also called endurants.

The conditions under which an object can be deemed to maintain its identity are often difficult to establish - the decision depends largely on the judgement of the observer. Most people would agree, for example, that a building ceases to exist if it is dismantled and the materials reused in a different configuration. Human beings, on the other hand, in common with many other organisms, go through radical and profound changes during their life-span, affecting both material composition and form, yet preserve their identity. But also material objects in daily use also undergo material changes due to maintenance etc. without changing identity. Identity in these cases would seem to depend more on continuity rather than the presence of any particular physical state or component.

The main classes of objects which fall outside the scope of E77 Persistent Item are Temporal Entities such as periods, events and
acts, and descriptive properties, (such as dimensions) which function as adjectives and adverbs. The latter depend in there identity on the object they are assigned to. The former acquire an identity only through the changes participating Persistent Items undergo, but not out of their own form or substance. We regard them as disjoint from Temporal Entities.

E18 Physical Stuff

Subclass of:

Legal Object

Superclass of:

Physical Object
Physical Man-Made Stuff
Physical Feature

Scope note:

Physical stuff is an abstract notion that groups all physical objects, man-made and natural, as well as physical features of objects, such as holes. We use the term 'feature' to refer to anything of a material nature, such as scratches, holes, rivers, and stains, which it would be strange to refer to as ?objects?.

New Scope note:

Physical stuff is an abstract notion that groups all physical objects, man-made and natural, as well as physical features of objects, such as holes. We use the term 'feature' to refer to anything of a material nature, such as scratches, holes, rivers, and stains, which it would be strange to refer to as ?objects?. Physical stuff is disjoint from E28 Conceptual Object, the immaterial products. The latter are exclusively man-made. Physical stuff can only be present at one place at a time, whereas conceptual objects may be present at multiple places at a time via multiple physical carriers. Physical stuff ceases to exist by destruction, whereas conceptual objects ceases to exist by loss of the last carrier or by forgetting.
Examples: Me, the Cave of Dirou in Peloponnese, the Euphrat River, Lassie the dog, the logbook of the Endeavor.

 

E28 Conceptual Object

Subclass of:

Man-Made Stuff

Superclas of:

Right
Information Object
Type

Scope note:

This entity is the attempt to group the non-material products of our minds, and specifically to allow for reasoning about their identity, circumstances of creation and historical implications. Characteristically, these things are created, invented or thought, and somehow documented or communicated between persons. Conceptual objects need not have a particular carrier, but may be found on several different carriers, such as paper, electronic signals, marks, audio media, paintings, photos, human memory, etc. They cannot be destroyed as long as they exist on at least one carrier or in memory. Examples include texts, maps, photos, music, sounds, fairy tales, signs, patterns, symbols, plans, rights, and rules. A greater distinction could be made between products having a clear identity, such as a specific text, or photographs, and the ideas and concepts shared and traded by groups of people.

New Scope Note:

This entity is the attempt to group the non-material products of our minds and of technical processes such as image taking, and specifically to allow for reasoning about their identity, circumstances of creation and historical implications. Characteristically, these things are created, invented or thought, and somehow documented or communicated between persons and technical means of communication. Conceptual objects need not have a particular carrier, but may be found on several different carriers, such as paper, electronic signals, marks, audio media, paintings, photos, human memory, etc. They cannot be destroyed as long as they exist on at least one carrier or in memory. Examples include texts, maps, photos, music, sounds, fairy tales, signs, patterns, symbols, plans, rights, rules, types, taxa and other concepts. A greater distinction is made between products having a clear identity, such as a specific text, or photographs, the Information Objects and the ideas and concepts shared and traded by groups of people. Conceptual objects are disjoint from physical stuff, the material things. The latter may be man-made or not. Physical stuff can only be present at one place at a time, whereas conceptual objects may be present at multiple places at a time via multiple physical carriers.
Examples: The contents of "Definition of the CIDOCobject-oriented Conceptual Reference Model, version 3.3.2, Sept.2002", the copyright by CIDOC on the latter, the species fringilla coelebs, the sound track of The Beatles "Yellow Submarine", Albrecht Durer's signature, Unicorn.

16/10/2002

Outcome: 

Solution in version 3.3.2 accepted. Text in introduction needs rewording.

Proposal Accepted

Rethymnon 22/10/2002