ISO 21127:2006

SLOVENSKI STANDARD
SIST ISO 21127:2009
01-december-2009
,QIRUPDWLNDLQGRNXPHQWDFLMD5HIHUHQþQDRQWRORJLMD]DL]PHQMDYRLQIRUPDFLMR
NXOWXUQLGHGLãþLQL
Information and documentation - A reference ontology for the interchange of cultural
heritage information
Information et documentation - Une ontologie de référence pour l'échange d'informations
du patrimoine culturel
Ta slovenski standard je istoveten z: ISO 21127:2006
ICS:
35.240.30 Uporabniške rešitve IT v IT applications in information,
informatiki, dokumentiranju in documentation and
založništvu publishing
SIST ISO 21127:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 21127:2009

---------------------- Page: 2 ----------------------

SIST ISO 21127:2009


INTERNATIONAL ISO
STANDARD 21127
First edition
2006-09-15

Information and documentation —
A reference ontology for the interchange
of cultural heritage information
Information et documentation — Une ontologie de référence pour
l'échange d'informations du patrimoine culturel




Reference number
ISO 21127:2006(E)
©
ISO 2006

---------------------- Page: 3 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2006 – All rights reserved

---------------------- Page: 4 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Conformance. 2
3 Terms and definitions. 2
4 Structure and presentation. 6
4.1 Property quantifiers. 6
4.2 Naming conventions. 8
5 Modelling principles . 8
5.1 Monotonicity. 8
5.2 Minimality . 9
5.3 Shortcuts . 9
5.4 Disjointness. 9
5.5 Types. 10
5.6 Extensions. 10
5.7 Coverage of intended scope. 11
6 Class declarations . 11
7 Property declarations. 55
Annex A (informative) Class hierarchy . 101
Annex B (informative) Property hierarchy . 103
Bibliography . 108

© ISO 2006 – All rights reserved iii

---------------------- Page: 5 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21127 was prepared by Technical Committee ISO/TC 46, Information and documentation, Subcommittee
SC 4, Technical interoperability, in collaboration with the International Council of Museums Committee for
Documentation (ICOM CIDOC).

iv © ISO 2006 – All rights reserved

---------------------- Page: 6 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
Introduction
This International Standard is the culmination of more than a decade of standards development work by the
International Committee for Documentation (CIDOC) of the International Council of Museums (ICOM). Work
on this International Standard began in 1996 under the auspices of the ICOM-CIDOC Documentation
Standards Working Group. Throughout its development, the model has been known as the “CIDOC
Conceptual Reference Model” or CRM. References to the CRM can be considered throughout as synonymous
with ISO 21127.
The primary purpose of this International Standard is to offer a conceptual basis for the mediation of
information between cultural heritage organizations such as museums, libraries and archives. This
International Standard aims to provide a common reference point against which divergent and incompatible
sources of information can be compared and, ultimately, harmonized.
1)
ISO 21127 is a domain ontology for cultural heritage information: a formal representation of the conceptual
scheme, or “world view”, underlying the database applications and documentation systems that are used by
cultural heritage institutions. It is important to note that this International Standard aims to clarify the logic of
what cultural heritage institutions do in fact document; it is not intended as a normative specification of what
they should document. The primary role of this International Standard is to enable information exchange and
integration between heterogeneous sources of cultural heritage information. It aims to provide the semantic
definitions and clarifications needed to transform disparate, localized information sources into a coherent
global resource, be it within an institution, an intranet or on the Internet.
The specific aims of this International Standard are to:
⎯ Serve as a common language for domain experts and IT developers when formulating requirements.
⎯ Serve as a formal language for the identification of common information contents in different data formats;
in particular to support the implementation of automatic data transformation algorithms from local to
global data structures without loss of meaning. These transformation algorithms are useful for data
exchange, data migration from legacy systems, data information integration, and mediation of
heterogeneous sources.
⎯ Support associative queries against integrated resources by providing a global model of the basic classes
and their associations to formulate such queries.
⎯ Provide developers of information systems with a guide to good practice in conceptual modelling.
The CRM ontology is expressed as a series of interrelated concepts with definitions. This presentation is
similar to that used for a thesaurus. However, the ontology is not intended as a terminology standard and
does not set out to define the terms that are typically used as data in cultural heritage documentation.
Although the presentation provided here is complete, it is an intentionally compact and concise presentation of
the ontology's 80 classes and 130 unique properties. It does not attempt to articulate the inheritance of
properties by subclasses throughout the class hierarchy (this would require the declaration of several
thousand properties, as opposed to 130). However, this definition does contain all the information needed to
infer and automatically generate a full declaration of all properties, including inherited properties.

1) In the sense used in computer science, i.e. it describes in a formal language the relevant explicit and implicit concepts
[1]
and the relationships between them .
© ISO 2006 – All rights reserved v

---------------------- Page: 7 ----------------------

SIST ISO 21127:2009

---------------------- Page: 8 ----------------------

SIST ISO 21127:2009
INTERNATIONAL STANDARD ISO 21127:2006(E)

Information and documentation — A reference ontology for
the interchange of cultural heritage information
1 Scope
This International Standard establishes guidelines for the exchange of information between cultural heritage
institutions. In simple terms this can be defined as the curated knowledge of museums.
A more detailed definition can be articulated by defining both the intended scope, a broad and maximally
inclusive definition of general principles, and the practical scope, which is defined by reference to a set of
specific museum documentation standards and practices.
The intended scope of this International Standard is defined as the exchange and integration of
heterogeneous scientific documentation relating to museum collections. This definition requires further
elaboration:
⎯ The term “scientific documentation” is intended to convey the requirement that the depth and quality of
descriptive information that can be handled by this International Standard need be sufficient for serious
academic research. This does not mean that information intended for presentation to members of the
general public is excluded, but rather that this International Standard is intended to provide the level of
detail and precision expected and required by museum professionals and researchers in the field.
⎯ The term “museum collections” is intended to cover all types of material collected and displayed by
2)
museums and related institutions, as defined by ICOM . This includes collections, sites, and monuments
relating to fields such as social history, ethnography, archaeology, fine and applied arts, natural history,
history of sciences and technology.
⎯ The documentation of collections includes the detailed description of individual items within collections,
groups of items and collections as a whole. This International Standard is specifically intended to cover
contextual information (i.e. the historical, geographical, and theoretical background that gives museum
collections much of their cultural significance and value).
⎯ The exchange of relevant information with libraries and archives, and harmonization with their models,
falls within the intended scope of this International Standard.
⎯ Information required solely for the administration and management of cultural institutions, such as
information relating to personnel, accounting and visitor statistics, falls outside the intended scope of this
International Standard.
3)
The practical scope of this International Standard is the set of reference standards for museum documentation
that have been used to guide and validate its development. This International Standard covers the same
domain of discourse as the union of these reference documents; this means that data correctly encoded
according to any of these reference documents can be expressed in a compatible form, without any loss of
meaning.

2) The ICOM Statutes provide a definition of the term “museum” at .
3) The practical scope of the CIDOC CRM, including a list of the relevant museum documentation standards, is
discussed in more detail on the CIDOC CRM website at .
© ISO 2006 – All rights reserved 1

---------------------- Page: 9 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
2 Conformance
Users intending to take advantage of the semantic interoperability offered by this International Standard
should ensure conformance with the relevant data structures. Conformance pertains either to data to be made
accessible in an integrated environment, or to contents intended for transport to other environments. Any
encoding of data in a formal language that preserves the relations of the classes, properties and inheritance
rules defined by this International Standard is regarded as conformant.
Conformance with this International Standard does not require complete matching of all local documentation
structures, nor that all concepts and structures present in this International Standard be implemented. This
International Standard is intended to allow room both for extensions, needed to capture the full richness of
cultural information, and for simplification, in the interests of economy. A system will be deemed partially
conformant if it supports a subset of subclasses and subproperties defined by this International Standard.
Designers of the system should publish details of the constructs that are supported.
The focus of this International Standard is on the transport and mediation of structured information. It does not
provide or require interpretation of unstructured free-text information into a structured, logical form. Free-text
information, while supported, falls outside the scope of conformance considerations.
Any documentation system will be deemed conformant with this International Standard, regardless of the
internal data structures it uses, if a deterministic logical algorithm can be constructed that transforms data
contained in the system into a directly compatible form without loss of meaning. No assumptions are made as
to the nature of this algorithm. “Without loss of meaning” signifies that designers and users of the system are
satisfied that the data representation corresponds to the semantic definitions provided by this International
Standard.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. We have selected these terms
for ease of understanding by non-computer experts from the various terminologies in use for object-oriented
models.
3.1
class
category of items that share one or more common properties
NOTE Class properties serve as criteria to identify items that belong to the class. These properties need not be
explicitly formulated in logical terms, but can be described in a text (called a scope note) that refers to a common
conceptualisation of domain experts. The sum of these properties is called the intension of the class. A class can be the
domain or range of none, one, or more properties formally defined in a model. The formally defined properties need not be
part of the intension of their domains or ranges: such properties are optional. An item that belongs to a class is called an
instance of this class. A class is associated with an open set of real-life instances, known as the extension of the class.
Here “open” is used in the sense that it is generally beyond our capabilities to know all instances of a class in the world
and, indeed, that the future can bring new instances into being at any time (Open World). Therefore a class cannot be
defined by enumerating its instances. A class plays a role analogous to a grammatical noun, and can be completely
defined without reference to any other construct (unlike properties, which need to have an unambiguously defined domain
and range). For example, “Person” is a class. A “Person” can have the property of being a member of a “Group”, but this is
not a necessary condition for being a “Person”. We will never know all “Persons” who have lived in the past, and there will
be more “Persons” in the future. Classes are usually organized as a class hierarchy. The relationship between a subclass
and its superclass is known as the IsA relationship (a concatenation of the words “is a”). For example, a ship IsA vehicle.
3.2
complement
〈of a class A〉 set of all instances of its superclass, B, that are not instances of class A
NOTE In terms of set theory, the complement of a class is the extension of the superclass minus the extension of the
class. Compatible extensions of this International Standard need not declare any class as the complement of one or more
other classes. To do so would violate the goal of describing an Open World. For example, for all possible cases of human
gender, “male” need not be declared as the complement of “female” or vice versa.
2 © ISO 2006 – All rights reserved

---------------------- Page: 10 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
3.3
disjoint
having no common instances in any possible world
NOTE 1 Classes are disjoint if the intersection of their extensions is necessarily an empty set.
NOTE 2 See also 5.4.
3.4
domain
class for which a property is formally defined
NOTE Instances of a property are applicable to instances of its domain class. A property needs to have exactly one
domain, though the domain class can always contain instances for which the property is not instantiated. The domain
class is analogous to the grammatical subject of a phrase while the property is analogous to the verb. Which class is
selected as the domain and which as the range is arbitrary, as is the choice between active or passive voice. Property
names in the CRM are designed to be semantically meaningful and grammatically correct when read from domain to
range. The inverse property name, given in parentheses, is also designed to be semantically meaningful and
grammatically correct when read from range to domain.
3.5
extension
set of all real life instances belonging to a class that fulfil the criteria of its intension
NOTE 1 The extension of a class is an “open” set in the sense that it is generally beyond our capabilities to know all
instances of a class in the world. The future can bring new instances into being at any time (Open World). An information
system may at any point in time refer to some instances of a class, which form a subset of its extension.
NOTE 2 See also 5.6.
3.6
inheritance
duplication of properties from a class to its subclasses
NOTE Inheritance of properties from superclasses to subclasses entails that if an item x is an instance of a class A,
then all properties that need hold for the instances of any of the superclasses of A need also hold for item x, and that all
optional properties that can hold for the instances of any of the superclasses of A can also hold for item x.
3.7
instance
item having properties that meet the criteria of the intension of the class
NOTE “The Mona Lisa” is an instance of the class of “physical man-made objects”. An instance of a property is a
factual relation between an instance of the domain and an instance of the range of the property that matches the criteria of
the intension of the property. For example, “the Louvre is current owner of the Mona Lisa” is an instance of the property “is
current owner of”. The number of instances of a class declared in an information system is usually less than the total
number of instances in the real world. For example, although you are an instance of “person”, you are not mentioned in all
information systems describing “persons”.
3.8
intension
intended meaning of a class
NOTE The intension of a class consists of one or more common properties, or traits shared by all instances of the
class. These properties need not be explicitly formulated in logical terms, but can simply be described in a text (a scope
note) that refers to a conceptualization shared by domain experts.
3.9
interoperability
capability of different information systems to communicate some of their contents
© ISO 2006 – All rights reserved 3

---------------------- Page: 11 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
NOTE Interoperability can imply that
a) two systems can exchange information, and/or
b) multiple systems can be accessed with a single method.
Generally, syntactic interoperability is distinguished from semantic interoperability. Syntactic interoperability means that
the information encoding and the access protocols of the relevant systems are compatible, so that information can be
processed as described above without error. However, syntactic interoperability alone does not ensure that each system
processes the data in a manner consistent with the intended meaning. For example, one system can use a table called
“Actor” and another one called “Agent”. Data from the two tables might remain separated, even though they can have
exactly the same meaning. To overcome this situation, semantic interoperability has to be added. The CRM relies on
existing syntactic interoperability and is concerned only with adding semantic interoperability.
3.10
monotonic
〈of a knowledge base〉 having a set of conclusions derived via inference rules that does not reduce,
irrespective of the whatever additional propositions can be inserted
NOTE 1 Monotonic reasoning is a term derived from knowledge representation. In practical terms, as experts enter
correct statements to an information system, the system need not regard any of the existing statements as invalid. The
CRM ontology is designed for monotonic reasoning and so enables conflict-free merging of huge stores of knowledge.
NOTE 2 See also 5.1.
3.11
multiple inheritance
possibility for a class to have more than one immediate superclass
NOTE The extension of a class with multiple immediate superclasses is a subset of the intersection of all extensions
of its superclasses. The intension of a class with multiple immediate superclasses extends the intensions of all its
superclasses, i.e. its traits are more restrictive than any of its superclasses. If multiple inheritance is used, the resulting
“class hierarchy” is a directed graph and not a tree structure. If it is represented as an indented list, then some classes will
inevitably be repeated at different positions in the hierarchy. For example, “person” is both an “actor” and a “biological
object”.
3.12
open world
assumption that the information stored in a knowledge base is incomplete with respect to the universe of
discourse it aims to describe
NOTE A term derived from knowledge representation. The incompleteness of a knowledge base can be due to the
inability of the maintainer to provide sufficient information, or to more fundamental problems of cognition in the system’s
domain. Such problems are characteristic of cultural information systems since our records about the past are necessarily
incomplete. In addition, some items cannot be clearly assigned to a given class. In particular, the absence of a certain
property for an item described in the system does not necessarily entail that the item does not possess the property. For
example, if one item is described as “biological object” and another as “physical object”, this does not imply that the latter
is not also a “biological object”. Therefore, complements of a class with respect to a superclass cannot be derived in
general from an information system based on the open world assumption.
3.13
primitive concept
concept that is declared and for which the meaning is clear, but which cannot be derived from other concepts
NOTE Primitive concept is a term derived from knowledge representation. For example, mother can be described as
a female who has given birth to a child, so mother is not a primitive concept. Event however is a primitive concept. The
CRM is composed primarily of primitive concepts.
3.14
property
defining characteristic that serves to define a relationship of a specific kind between two classes
4 © ISO 2006 – All rights reserved

---------------------- Page: 12 ----------------------

SIST ISO 21127:2009
ISO 21127:2006(E)
NOTE A property is characterized by an intension, which is conveyed by a scope note. A property plays a role
analogous to a verb in that it need be defined with reference to both a domain and range, which are analogous to the
subject and object in a phrase (unlike classes, which can be defined independently). Which class is selected as the
domain and which as the range, is arbitrary, as is the choice between active and passive voice. In other words, a property
can be interpreted in both directions, with two distinct but related interpretations. Properties can themselves have
properties that relate to other classes. (This feature is used in this model only in order to describe dynamic subtyping of
properties.) Properties can also be specialized in the same manner as classes, resulting in IsA relationships between
subproperties and their superproperties. For example, “physical man-made thing depicts CRM entity” is equivalent to
“CRM entity is depicted by physical man-made thing”.
3.15
query containment
query X contains another query Y if, for each possible population of a database, the answer set to query X also
contains the answer set to query Y
NOTE If query X and Y were classes, then X would be a superclass of Y.
3.16
range
class that comprises all the potential values of a property
NOTE Instances of a property can only link to instances of its range class. A property needs to have exactly one
range, though the range class can also contain instances that are not values of the property. The range class is analogous
to the grammatical object of a phrase, while the property is analogous to the verb. Which class is selected as domain, and
which as range, is arbitrary, as is the choice between active and passive voice. Property names in the CRM are designed
to be semantically meaningful and grammatically correct when read from domain to range. The inverse property name,
given in parentheses, is designed to be semantically meaningful and grammatically correct when read from range to
domain.
3.17
scope note
textual description of the intension of a class or property
NOTE Scope notes are not formal modelling constructs but are provided to help explain the intended meaning and
application of the CRM’s classes and properties. Basically, they refer to a conceptualization shared by domain experts and
disambiguate different possible interpretations. Illustrative examples of classes and properties are also provided with the
scope notes for explanatory purposes.
3.18
shortcut
formally defined single property that represents a deduction or join of a data path in the CRM
NOTE 1 The scope notes of shortcut properties provide a verbal description of the equivalen
...

SLOVENSKI STANDARD
oSIST ISO 21127:2007
01-april-2007
,QIRUPDWLNDLQGRNXPHQWDFLMD5HIHUHQþQDRQWRORJLMD]DL]PHQMDYRLQIRUPDFLMR
NXOWXUQLGHGLãþLQL
Information and documentation - A reference ontology for the interchange of cultural
heritage information
Ta slovenski standard je istoveten z:
ICS:
35.240.30 Uporabniške rešitve IT v IT applications in information,
informatiki, dokumentiranju in documentation and
založništvu publishing
oSIST ISO 21127:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

INTERNATIONAL ISO
STANDARD 21127
First edition
2006-09-15

Information and documentation —
A reference ontology for the interchange
of cultural heritage information
Information et documentation — Une ontologie de référence pour
l'échange d'informations du patrimoine culturel




Reference number
ISO 21127:2006(E)
©
ISO 2006

---------------------- Page: 2 ----------------------

ISO 21127:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2006 – All rights reserved

---------------------- Page: 3 ----------------------

ISO 21127:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Conformance. 2
3 Terms and definitions. 2
4 Structure and presentation. 6
4.1 Property quantifiers. 6
4.2 Naming conventions. 8
5 Modelling principles . 8
5.1 Monotonicity. 8
5.2 Minimality . 9
5.3 Shortcuts . 9
5.4 Disjointness. 9
5.5 Types. 10
5.6 Extensions. 10
5.7 Coverage of intended scope. 11
6 Class declarations . 11
7 Property declarations. 55
Annex A (informative) Class hierarchy . 101
Annex B (informative) Property hierarchy . 103
Bibliography . 108

© ISO 2006 – All rights reserved iii

---------------------- Page: 4 ----------------------

ISO 21127:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21127 was prepared by Technical Committee ISO/TC 46, Information and documentation, Subcommittee
SC 4, Technical interoperability, in collaboration with the International Council of Museums Committee for
Documentation (ICOM CIDOC).

iv © ISO 2006 – All rights reserved

---------------------- Page: 5 ----------------------

ISO 21127:2006(E)
Introduction
This International Standard is the culmination of more than a decade of standards development work by the
International Committee for Documentation (CIDOC) of the International Council of Museums (ICOM). Work
on this International Standard began in 1996 under the auspices of the ICOM-CIDOC Documentation
Standards Working Group. Throughout its development, the model has been known as the “CIDOC
Conceptual Reference Model” or CRM. References to the CRM can be considered throughout as synonymous
with ISO 21127.
The primary purpose of this International Standard is to offer a conceptual basis for the mediation of
information between cultural heritage organizations such as museums, libraries and archives. This
International Standard aims to provide a common reference point against which divergent and incompatible
sources of information can be compared and, ultimately, harmonized.
1)
ISO 21127 is a domain ontology for cultural heritage information: a formal representation of the conceptual
scheme, or “world view”, underlying the database applications and documentation systems that are used by
cultural heritage institutions. It is important to note that this International Standard aims to clarify the logic of
what cultural heritage institutions do in fact document; it is not intended as a normative specification of what
they should document. The primary role of this International Standard is to enable information exchange and
integration between heterogeneous sources of cultural heritage information. It aims to provide the semantic
definitions and clarifications needed to transform disparate, localized information sources into a coherent
global resource, be it within an institution, an intranet or on the Internet.
The specific aims of this International Standard are to:
⎯ Serve as a common language for domain experts and IT developers when formulating requirements.
⎯ Serve as a formal language for the identification of common information contents in different data formats;
in particular to support the implementation of automatic data transformation algorithms from local to
global data structures without loss of meaning. These transformation algorithms are useful for data
exchange, data migration from legacy systems, data information integration, and mediation of
heterogeneous sources.
⎯ Support associative queries against integrated resources by providing a global model of the basic classes
and their associations to formulate such queries.
⎯ Provide developers of information systems with a guide to good practice in conceptual modelling.
The CRM ontology is expressed as a series of interrelated concepts with definitions. This presentation is
similar to that used for a thesaurus. However, the ontology is not intended as a terminology standard and
does not set out to define the terms that are typically used as data in cultural heritage documentation.
Although the presentation provided here is complete, it is an intentionally compact and concise presentation of
the ontology's 80 classes and 130 unique properties. It does not attempt to articulate the inheritance of
properties by subclasses throughout the class hierarchy (this would require the declaration of several
thousand properties, as opposed to 130). However, this definition does contain all the information needed to
infer and automatically generate a full declaration of all properties, including inherited properties.

1) In the sense used in computer science, i.e. it describes in a formal language the relevant explicit and implicit concepts
[1]
and the relationships between them .
© ISO 2006 – All rights reserved v

---------------------- Page: 6 ----------------------

INTERNATIONAL STANDARD ISO 21127:2006(E)

Information and documentation — A reference ontology for
the interchange of cultural heritage information
1 Scope
This International Standard establishes guidelines for the exchange of information between cultural heritage
institutions. In simple terms this can be defined as the curated knowledge of museums.
A more detailed definition can be articulated by defining both the intended scope, a broad and maximally
inclusive definition of general principles, and the practical scope, which is defined by reference to a set of
specific museum documentation standards and practices.
The intended scope of this International Standard is defined as the exchange and integration of
heterogeneous scientific documentation relating to museum collections. This definition requires further
elaboration:
⎯ The term “scientific documentation” is intended to convey the requirement that the depth and quality of
descriptive information that can be handled by this International Standard need be sufficient for serious
academic research. This does not mean that information intended for presentation to members of the
general public is excluded, but rather that this International Standard is intended to provide the level of
detail and precision expected and required by museum professionals and researchers in the field.
⎯ The term “museum collections” is intended to cover all types of material collected and displayed by
2)
museums and related institutions, as defined by ICOM . This includes collections, sites, and monuments
relating to fields such as social history, ethnography, archaeology, fine and applied arts, natural history,
history of sciences and technology.
⎯ The documentation of collections includes the detailed description of individual items within collections,
groups of items and collections as a whole. This International Standard is specifically intended to cover
contextual information (i.e. the historical, geographical, and theoretical background that gives museum
collections much of their cultural significance and value).
⎯ The exchange of relevant information with libraries and archives, and harmonization with their models,
falls within the intended scope of this International Standard.
⎯ Information required solely for the administration and management of cultural institutions, such as
information relating to personnel, accounting and visitor statistics, falls outside the intended scope of this
International Standard.
3)
The practical scope of this International Standard is the set of reference standards for museum documentation
that have been used to guide and validate its development. This International Standard covers the same
domain of discourse as the union of these reference documents; this means that data correctly encoded
according to any of these reference documents can be expressed in a compatible form, without any loss of
meaning.

2) The ICOM Statutes provide a definition of the term “museum” at .
3) The practical scope of the CIDOC CRM, including a list of the relevant museum documentation standards, is
discussed in more detail on the CIDOC CRM website at .
© ISO 2006 – All rights reserved 1

---------------------- Page: 7 ----------------------

ISO 21127:2006(E)
2 Conformance
Users intending to take advantage of the semantic interoperability offered by this International Standard
should ensure conformance with the relevant data structures. Conformance pertains either to data to be made
accessible in an integrated environment, or to contents intended for transport to other environments. Any
encoding of data in a formal language that preserves the relations of the classes, properties and inheritance
rules defined by this International Standard is regarded as conformant.
Conformance with this International Standard does not require complete matching of all local documentation
structures, nor that all concepts and structures present in this International Standard be implemented. This
International Standard is intended to allow room both for extensions, needed to capture the full richness of
cultural information, and for simplification, in the interests of economy. A system will be deemed partially
conformant if it supports a subset of subclasses and subproperties defined by this International Standard.
Designers of the system should publish details of the constructs that are supported.
The focus of this International Standard is on the transport and mediation of structured information. It does not
provide or require interpretation of unstructured free-text information into a structured, logical form. Free-text
information, while supported, falls outside the scope of conformance considerations.
Any documentation system will be deemed conformant with this International Standard, regardless of the
internal data structures it uses, if a deterministic logical algorithm can be constructed that transforms data
contained in the system into a directly compatible form without loss of meaning. No assumptions are made as
to the nature of this algorithm. “Without loss of meaning” signifies that designers and users of the system are
satisfied that the data representation corresponds to the semantic definitions provided by this International
Standard.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. We have selected these terms
for ease of understanding by non-computer experts from the various terminologies in use for object-oriented
models.
3.1
class
category of items that share one or more common properties
NOTE Class properties serve as criteria to identify items that belong to the class. These properties need not be
explicitly formulated in logical terms, but can be described in a text (called a scope note) that refers to a common
conceptualisation of domain experts. The sum of these properties is called the intension of the class. A class can be the
domain or range of none, one, or more properties formally defined in a model. The formally defined properties need not be
part of the intension of their domains or ranges: such properties are optional. An item that belongs to a class is called an
instance of this class. A class is associated with an open set of real-life instances, known as the extension of the class.
Here “open” is used in the sense that it is generally beyond our capabilities to know all instances of a class in the world
and, indeed, that the future can bring new instances into being at any time (Open World). Therefore a class cannot be
defined by enumerating its instances. A class plays a role analogous to a grammatical noun, and can be completely
defined without reference to any other construct (unlike properties, which need to have an unambiguously defined domain
and range). For example, “Person” is a class. A “Person” can have the property of being a member of a “Group”, but this is
not a necessary condition for being a “Person”. We will never know all “Persons” who have lived in the past, and there will
be more “Persons” in the future. Classes are usually organized as a class hierarchy. The relationship between a subclass
and its superclass is known as the IsA relationship (a concatenation of the words “is a”). For example, a ship IsA vehicle.
3.2
complement
〈of a class A〉 set of all instances of its superclass, B, that are not instances of class A
NOTE In terms of set theory, the complement of a class is the extension of the superclass minus the extension of the
class. Compatible extensions of this International Standard need not declare any class as the complement of one or more
other classes. To do so would violate the goal of describing an Open World. For example, for all possible cases of human
gender, “male” need not be declared as the complement of “female” or vice versa.
2 © ISO 2006 – All rights reserved

---------------------- Page: 8 ----------------------

ISO 21127:2006(E)
3.3
disjoint
having no common instances in any possible world
NOTE 1 Classes are disjoint if the intersection of their extensions is necessarily an empty set.
NOTE 2 See also 5.4.
3.4
domain
class for which a property is formally defined
NOTE Instances of a property are applicable to instances of its domain class. A property needs to have exactly one
domain, though the domain class can always contain instances for which the property is not instantiated. The domain
class is analogous to the grammatical subject of a phrase while the property is analogous to the verb. Which class is
selected as the domain and which as the range is arbitrary, as is the choice between active or passive voice. Property
names in the CRM are designed to be semantically meaningful and grammatically correct when read from domain to
range. The inverse property name, given in parentheses, is also designed to be semantically meaningful and
grammatically correct when read from range to domain.
3.5
extension
set of all real life instances belonging to a class that fulfil the criteria of its intension
NOTE 1 The extension of a class is an “open” set in the sense that it is generally beyond our capabilities to know all
instances of a class in the world. The future can bring new instances into being at any time (Open World). An information
system may at any point in time refer to some instances of a class, which form a subset of its extension.
NOTE 2 See also 5.6.
3.6
inheritance
duplication of properties from a class to its subclasses
NOTE Inheritance of properties from superclasses to subclasses entails that if an item x is an instance of a class A,
then all properties that need hold for the instances of any of the superclasses of A need also hold for item x, and that all
optional properties that can hold for the instances of any of the superclasses of A can also hold for item x.
3.7
instance
item having properties that meet the criteria of the intension of the class
NOTE “The Mona Lisa” is an instance of the class of “physical man-made objects”. An instance of a property is a
factual relation between an instance of the domain and an instance of the range of the property that matches the criteria of
the intension of the property. For example, “the Louvre is current owner of the Mona Lisa” is an instance of the property “is
current owner of”. The number of instances of a class declared in an information system is usually less than the total
number of instances in the real world. For example, although you are an instance of “person”, you are not mentioned in all
information systems describing “persons”.
3.8
intension
intended meaning of a class
NOTE The intension of a class consists of one or more common properties, or traits shared by all instances of the
class. These properties need not be explicitly formulated in logical terms, but can simply be described in a text (a scope
note) that refers to a conceptualization shared by domain experts.
3.9
interoperability
capability of different information systems to communicate some of their contents
© ISO 2006 – All rights reserved 3

---------------------- Page: 9 ----------------------

ISO 21127:2006(E)
NOTE Interoperability can imply that
a) two systems can exchange information, and/or
b) multiple systems can be accessed with a single method.
Generally, syntactic interoperability is distinguished from semantic interoperability. Syntactic interoperability means that
the information encoding and the access protocols of the relevant systems are compatible, so that information can be
processed as described above without error. However, syntactic interoperability alone does not ensure that each system
processes the data in a manner consistent with the intended meaning. For example, one system can use a table called
“Actor” and another one called “Agent”. Data from the two tables might remain separated, even though they can have
exactly the same meaning. To overcome this situation, semantic interoperability has to be added. The CRM relies on
existing syntactic interoperability and is concerned only with adding semantic interoperability.
3.10
monotonic
〈of a knowledge base〉 having a set of conclusions derived via inference rules that does not reduce,
irrespective of the whatever additional propositions can be inserted
NOTE 1 Monotonic reasoning is a term derived from knowledge representation. In practical terms, as experts enter
correct statements to an information system, the system need not regard any of the existing statements as invalid. The
CRM ontology is designed for monotonic reasoning and so enables conflict-free merging of huge stores of knowledge.
NOTE 2 See also 5.1.
3.11
multiple inheritance
possibility for a class to have more than one immediate superclass
NOTE The extension of a class with multiple immediate superclasses is a subset of the intersection of all extensions
of its superclasses. The intension of a class with multiple immediate superclasses extends the intensions of all its
superclasses, i.e. its traits are more restrictive than any of its superclasses. If multiple inheritance is used, the resulting
“class hierarchy” is a directed graph and not a tree structure. If it is represented as an indented list, then some classes will
inevitably be repeated at different positions in the hierarchy. For example, “person” is both an “actor” and a “biological
object”.
3.12
open world
assumption that the information stored in a knowledge base is incomplete with respect to the universe of
discourse it aims to describe
NOTE A term derived from knowledge representation. The incompleteness of a knowledge base can be due to the
inability of the maintainer to provide sufficient information, or to more fundamental problems of cognition in the system’s
domain. Such problems are characteristic of cultural information systems since our records about the past are necessarily
incomplete. In addition, some items cannot be clearly assigned to a given class. In particular, the absence of a certain
property for an item described in the system does not necessarily entail that the item does not possess the property. For
example, if one item is described as “biological object” and another as “physical object”, this does not imply that the latter
is not also a “biological object”. Therefore, complements of a class with respect to a superclass cannot be derived in
general from an information system based on the open world assumption.
3.13
primitive concept
concept that is declared and for which the meaning is clear, but which cannot be derived from other concepts
NOTE Primitive concept is a term derived from knowledge representation. For example, mother can be described as
a female who has given birth to a child, so mother is not a primitive concept. Event however is a primitive concept. The
CRM is composed primarily of primitive concepts.
3.14
property
defining characteristic that serves to define a relationship of a specific kind between two classes
4 © ISO 2006 – All rights reserved

---------------------- Page: 10 ----------------------

ISO 21127:2006(E)
NOTE A property is characterized by an intension, which is conveyed by a scope note. A property plays a role
analogous to a verb in that it need be defined with reference to both a domain and range, which are analogous to the
subject and object in a phrase (unlike classes, which can be defined independently). Which class is selected as the
domain and which as the range, is arbitrary, as is the choice between active and passive voice. In other words, a property
can be interpreted in both directions, with two distinct but related interpretations. Properties can themselves have
properties that relate to other classes. (This feature is used in this model only in order to describe dynamic subtyping of
properties.) Properties can also be specialized in the same manner as classes, resulting in IsA relationships between
subproperties and their superproperties. For example, “physical man-made thing depicts CRM entity” is equivalent to
“CRM entity is depicted by physical man-made thing”.
3.15
query containment
query X contains another query Y if, for each possible population of a database, the answer set to query X also
contains the answer set to query Y
NOTE If query X and Y were classes, then X would be a superclass of Y.
3.16
range
class that comprises all the potential values of a property
NOTE Instances of a property can only link to instances of its range class. A property needs to have exactly one
range, though the range class can also contain instances that are not values of the property. The range class is analogous
to the grammatical object of a phrase, while the property is analogous to the verb. Which class is selected as domain, and
which as range, is arbitrary, as is the choice between active and passive voice. Property names in the CRM are designed
to be semantically meaningful and grammatically correct when read from domain to range. The inverse property name,
given in parentheses, is designed to be semantically meaningful and grammatically correct when read from range to
domain.
3.17
scope note
textual description of the intension of a class or property
NOTE Scope notes are not formal modelling constructs but are provided to help explain the intended meaning and
application of the CRM’s classes and properties. Basically, they refer to a conceptualization shared by domain experts and
disambiguate different possible interpretations. Illustrative examples of classes and properties are also provided with the
scope notes for explanatory purposes.
3.18
shortcut
formally defined single property that represents a deduction or join of a data path in the CRM
NOTE 1 The scope notes of shortcut properties provide a verbal description of the equivalent deduction. Shortcuts are
introduced for those cases where common documentation practice refers only to the deduction rather than to the fully
developed path. For example, museums often only record the “dimension” of an object without documenting the
E16 measurement activity that observed it. The CRM allows shortcuts as cases of less detailed knowledge, while
preserving in its schema the relationship to the full information.
NOTE 2 See also 5.3.
3.19
strict inheritance
properties
...

NORME ISO
INTERNATIONALE 21127
Première édition
2006-09-15


Information et documentation —
Une ontologie de référence pour
l'échange d'informations du patrimoine
culturel
Information and documentation — A reference ontology for
the interchange of cultural heritage information




Numéro de référence
ISO 21127:2006(F)
©
ISO 2006

---------------------- Page: 1 ----------------------
ISO 21127:2006(F)
PDF – Exonération de responsabilité
Le présent fichier PDF peut contenir des polices de caractères intégrées. Conformément aux conditions de licence d'Adobe, ce fichier
peut être imprimé ou visualisé, mais ne doit pas être modifié à moins que l'ordinateur employé à cet effet ne bénéficie d'une licence
autorisant l'utilisation de ces polices et que celles-ci y soient installées. Lors du téléchargement de ce fichier, les parties concernées
acceptent de fait la responsabilité de ne pas enfreindre les conditions de licence d'Adobe. Le Secrétariat central de l'ISO décline toute
responsabilité en la matière.
Adobe est une marque déposée d'Adobe Systems Incorporated.
Les détails relatifs aux produits logiciels utilisés pour la création du présent fichier PDF sont disponibles dans la rubrique General Info
du fichier; les paramètres de création PDF ont été optimisés pour l'impression. Toutes les mesures ont été prises pour garantir
l'exploitation de ce fichier par les comités membres de l'ISO. Dans le cas peu probable où surviendrait un problème d'utilisation,
veuillez en informer le Secrétariat central à l'adresse donnée ci-dessous.


©  ISO 2006
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit
de l'ISO à l'adresse ci-après ou du comité membre de l'ISO dans le pays du demandeur.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax. + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Publié en Suisse

ii © ISO 2006 – Tous droits réservés

---------------------- Page: 2 ----------------------
ISO 21127:2006(F)
Sommaire Page
Avant-propos. iv
Introduction . v
1 Domaine d'application. 1
2 Conformité. 2
3 Termes et définitions. 2
4 Structure et présentation . 7
4.1 Quantificateurs de propriété. 7
4.2 Conventions d'appellation. 8
5 Principes de modélisation . 9
5.1 Monotonicité. 9
5.2 Minimalité . 9
5.3 Raccourcis. 9
5.4 Classes disjointes. 10
5.5 Types. 10
5.6 Extensions. 11
5.7 Couverture du domaine d'application théorique. 11
6 Déclaration des classes . 12
7 Déclaration des propriétés . 60
Annexe A (informative) Hiérarchie des classes . 109
Annexe B (informative) Hiérarchie des propriétés. 111
Bibliographie . 116

© ISO 2006 – Tous droits réservés iii

---------------------- Page: 3 ----------------------
ISO 21127:2006(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 21127 a été élaborée par le comité technique ISO/TC 46, Information et documentation, sous-comité
SC 4, Interopérabilité technique, en collaboration avec le Comité pour la Documentation du Conseil
International des Musées (ICOM-CIDOC).

iv © ISO 2006 – Tous droits réservés

---------------------- Page: 4 ----------------------
ISO 21127:2006(F)
Introduction
La présente Norme internationale est l'aboutissement de plus d'une décennie de travail de la part du Comité
international pour la Documentation (CIDOC) du Conseil international des musées (ICOM). Le travail sur la
présente Norme internationale a commencé en 1996 sous les auspices du groupe de travail de l'ICOM-
CIDOC sur la normalisation documentaire. Tout au long de son élaboration, le modèle a été connu sous
l'appellation «CIDOC conceptual reference model» (le modèle conceptuel de référence du CIDOC) ou CRM.
Des références au CRM dans le présent document peuvent être considérées comme synonymes de
l'ISO 21127.
Le but primaire de la présente Norme internationale est d'offrir une base conceptuelle pour la médiation
d'informations entre les institutions de patrimoine culturel tels que les musées, les bibliothèques et les
archives. L'intention est de fournir un point de référence commun avec lequel des sources d'information
divergentes et incompatibles peuvent être comparées et, finalement, harmonisées.
1)
L'ISO 21127 est une ontologie formelle de domaine pour les informations concernant le patrimoine culturel:
c'est une représentation formelle du schéma conceptuel, ou «point de vue», qui est sous-jacent aux
applications de base de données et aux systèmes de documentation qui sont employés par les institutions de
patrimoine culturel. Il est important de noter que la présente Norme internationale vise à clarifier la logique de
ce que ces institutions documentent en pratique, et non pas à fournir des spécifications normatives de ce qu'il
convient qu'elles documentent. L'objectif primaire de la présente Norme internationale est de permettre
l'échange d'informations et l'intégration de sources hétérogènes d'informations sur le patrimoine culturel. Elle
établit les définitions et les clarifications sémantiques requises pour transformer les sources d'informations
localisées et disparates en une ressource globale, que ce soit dans le contexte d'une institution, d'un intranet
ou sur Internet.
Les objectifs spécifiques de la présente Norme internationale sont de
⎯ servir de langage commun entre experts du domaine et informaticiens, lors de l'élaboration d'un cahier
des charges,
⎯ servir de langage formel pour l'identification du contenu partagé entre diverses sources de données; en
particulier pour faciliter la conception d'algorithmes automatiques pour la transformation et le transfert de
données entre systèmes sans perte de signification. Ces algorithmes de transformation sont utiles pour
l'échange de données, la récupération de données depuis des systèmes existants, l'intégration des
informations et la médiation de sources de données hétérogènes,
⎯ permettre l'interrogation de ressources intégrées en fournissant un modèle global des classes de base et
de leurs associations pour formuler de telles questions,
⎯ fournir à des réalisateurs de systèmes d'information un guide de bonne pratique dans la modélisation
conceptuelle.

1) Dans le sens utilisé par les sciences de l'information, c'est à dire qu'il décrit dans un langage formel tous les concepts
[1]
explicites et implicites utilisés dans le domaine et les relations entre eux .
© ISO 2006 – Tous droits réservés v

---------------------- Page: 5 ----------------------
ISO 21127:2006(F)
L'ontologie du CRM consiste en une série de concepts et de définitions. Cette présentation est semblable à
celle utilisée pour un thesaurus. Cependant, l'ontologie ne doit pas être considérée comme un standard
terminologique et n'offre pas une définition de tous les termes qui sont typiquement employés comme
données dans la documentation des biens culturels. La présentation fournie ici est complète, mais
intentionnellement compacte et concise. Les 80 classes et les 130 propriétés dont l'ontologie se compose
sont définies sans que l'héritage des propriétés par des sous-classes soit explicité. (Au lieu de 130 propriétés,
cela exigerait la déclaration de plusieurs milliers). Cependant, cette définition contient toute l'information
requise pour développer et pour produire une déclaration complète de toutes les propriétés, y compris les
propriétés héritées.

vi © ISO 2006 – Tous droits réservés

---------------------- Page: 6 ----------------------
NORME INTERNATIONALE ISO 21127:2006(F)

Information et documentation — Une ontologie de référence
pour l'échange d'informations du patrimoine culturel
1 Domaine d'application
La présente Norme internationale donne des lignes directrices pour l'échange d'informations entre institutions
responsables du patrimoine culturel. Ceci peut être défini en termes plus simples comme la connaissance des
conservateurs de musées.
Une définition plus détaillée peut être formulée en définissant le domaine d'application de principe, une
définition large et inclusive basée sur des principes généraux, et le domaine d'application pratique, qui est
défini par référence à une série de normes et de pratiques de documentation utilisées par les musées.
Le domaine d'application de principe de la présente Norme internationale peut être défini comme toutes les
informations nécessaires pour l'échange et l'intégration de la documentation scientifique des collections de
musée. Cette définition peut être développée:
⎯ Le terme «documentation scientifique» est censé exprimer l'exigence que la profondeur et la qualité
d'informations descriptives qui peuvent être traitées par la présente Norme internationale ont besoin
d'être suffisantes pour la recherche académique et scientifique. Cette exigence ne signifie pas pour
autant que des informations destinées à la présentation au public ne sont pas prises en compte, mais
surtout que la présente Norme internationale est destinée à supporter le niveau de détail et de précision
exigés par des professionnels des musées et des chercheurs dans le domaine.
⎯ Le terme «collections de musées» englobe tout type de matériel rassemblé et exposé par des musées et
2)
des institutions apparentées, selon la définition de l'ICOM . Ceci inclut des collections, des sites et des
monuments en rapport avec des domaines tels que l'histoire sociale, l'ethnographie, l'archéologie, les
beaux-arts et les arts appliqués, l'histoire naturelle, l'histoire des sciences et de la technologie.
⎯ La documentation des collections inclut la description détaillée d'objets individuels qui font partie des
collections ainsi que des groupes d'objets et des collections dans leur ensemble. La présente Norme
internationale est spécifiquement censée couvrir des informations contextuelles (c'est-à-dire historiques,
géographiques et théoriques qui donnent aux collections de musée leur signification culturelle et leur
valeur).
⎯ L'échange des informations avec les bibliothèques et les archives et l'harmonisation avec leurs modèles
relève du domaine d'application de la présente Norme internationale.
⎯ Les informations exigées seulement pour l'administration et la gestion des institutions culturelles, telles
que les informations concernant la gestion personnelle, la comptabilité et les statistiques des visiteurs,
échappent au domaine d'application de principe de la présente Norme internationale.
3)
Le domaine d'application pratique de la présente Norme internationale est un ensemble de normes de
référence pour la documentation des collections des musées, employées lors de son élaboration pour guider

2) Les statuts de l'ICOM offrent une définition du terme «musée» à .
3) Le domaine d'application pratique du CIDOC CRM, y compris une liste des normes de documentation pour les
musées, est présenté plus en détail sur le site Web du CIDOC CRM à .
© ISO 2006 – Tous droits réservés 1

---------------------- Page: 7 ----------------------
ISO 21127:2006(F)
et pour valider son développement. La présente Norme internationale couvre le même domaine de discours
que l'ensemble de ces documents de référence; cela signifie que les données correctement codées selon
n'importe lequel de ces documents de référence peuvent être exprimées dans une forme compatible avec la
présente Norme internationale sans aucune perte de signification.
2 Conformité
Il convient que les utilisateurs censés profiter de l'interopérabilité sémantique offerte par la présente Norme
internationale assurent la conformité des structures de données appropriées. La conformité concerne soit les
données qu'il convient de rendre accessibles dans un environnement intégré, soit le contenu destiné à être
transporté vers d'autres environnements. N'importe quel codage de données dans un langage formel qui
préserve les relations entre les classes, les propriétés et les règles d'héritage définies par la présente Norme
internationale est considéré comme conforme.
La conformité avec la présente Norme internationale n'exige ni une correspondance complète de toutes les
structures de documentation locales, ni que tous les concepts et les structures définis par la présente Norme
internationale soient mis en œuvre. La conception de la Norme est telle que les extensions sont possibles,
souvent nécessaires pour englober toute la richesse des informations culturelles, ainsi que des simplifications,
pour des raisons d'économie. Un système sera considéré comme partiellement conforme s'il supporte un
sous-ensemble de classes et de propriétés définies par la présente Norme internationale. Il convient que les
concepteurs du système publient les détails des éléments qui sont supportés.
L'intérêt primaire de la présente Norme internationale est le transport et la médiation d'informations
structurées. Il ne permet ni ne requiert l'interprétation d'informations sous forme de texte libre vers une forme
structurée et logique. Les informations sous forme de texte libre, bien que rendues possibles, ne sont pas
visées par ces considérations sur la conformité.
On considérera n'importe quel système de documentation conforme avec la présente Norme internationale,
indépendamment de la structure interne de données qu'il emploie, si un algorithme logique qui transforme les
données enregistrées par le système dans une forme directement compatible avec la norme, sans perte de
signification, peut être construit. Aucune supposition n'est faite quant à la nature de cet algorithme. «Sans
perte de signification» indique que les concepteurs et les utilisateurs du système sont satisfaits de la
correspondance de la représentation des données avec les définitions sémantiques fournies par la présente
Norme internationale.
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s'appliquent. Nous avons choisi ces
termes à partir des diverses terminologies utilisées pour la description des modèles orientés objet dans le but
de faciliter la compréhension par des non-informaticiens.
3.1
classe
catégorie d’items qui partagent un ou plusieurs attributs
NOTE Les attributs d'une classe servent de critères pour l'identification des membres de la classe. Ces attributs n'ont
pas besoin d'être explicitement formulés en termes logiques, mais peuvent être décrits dans un texte (appelé ici une note
d'application) qui fait référence à une conceptualisation commune aux experts du domaine. La somme de ces attributs est
appelée l'intension de la classe. Une classe peut être le domaine ou la cible de zéro, une seule ou plusieurs propriétés
formellement définies dans un modèle. Les propriétés formellement définies n'ont pas besoin de faire partie de l'intension
de leurs domaines ou de leurs cibles: de telles propriétés sont facultatives. Un article qui appartient à une classe est
appelé une instance de cette classe. Une classe est associée à un ensemble ouvert d'instances réelles, qui constituent
l'extension de la classe. Ici le terme «ouvert» signifie qu'il est en général au-delà de nos capacités de connaître tous les
cas d'une classe dans le monde. L'avenir peut, d'ailleurs, révéler de nouveaux cas à tout moment (Monde Ouvert). Une
classe ne peut être définie par l'énumération de ses instances. Une classe joue un rôle analogue à un groupe nominal et
peut être complètement définie indépendamment de tout autre élément (à la différence des propriétés, qui doivent être
définies par rapport à un domaine et une cible). Par exemple «Personne» est une classe. Une «Personne» peut être
membre d'un «Groupe», mais il n'est pas nécessaire d'appartenir à un «Groupe» pour être une Personne. Nous n'aurons
2 © ISO 2006 – Tous droits réservés

---------------------- Page: 8 ----------------------
ISO 21127:2006(F)
jamais les connaissances complètes concernant toutes les «Personnes» qui ont vécu et il y aura plus de «Personnes» à
l'avenir. Les classes sont normalement organisées dans une hiérarchie de classes. La relation entre une sous-classe et sa
super-classe est appelée EstUn (la concaténation des mots «est un»). Par exemple un bateau EstUn véhicule.
3.2
complément
〈d'une classe A〉 ensemble de toutes les instances de sa super-classe, B, qui ne sont pas des instances de A
NOTE En termes de la théorie des ensembles, le complément d'une classe est l'extension de sa super-classe moins
l'extension de la classe. Les extensions compatibles avec la présente Norme internationale ne doivent pas déclarer une
classe dans le but de former le complément d'une ou de plusieurs autres classes. Ceci est en contradiction avec l'objectif
de décrire un Monde Ouvert. Par exemple pour tous les cas possibles de genre humain, on ne doit pas déclarer «mâle»
comme étant le complément de «femelle» ou vice versa.
3.3
classes disjointes
n'ayant pas d'instances communes dans n'importe quel monde envisageable
NOTE 1 Deux classes sont disjointes si l'intersection de leurs extensions est nécessairement un ensemble vide.
NOTE 2 Voir aussi 5.4.
3.4
domaine
classe pour laquelle une propriété est formellement définie
NOTE Les instances d'une propriété sont applicables aux instances de sa classe de domaine. Une propriété doit
avoir exactement un domaine, bien que la classe de domaine puisse toujours contenir des instances pour lesquelles la
propriété n'est pas instanciée. La classe de domaine est analogue au sujet grammatical d'une phrase; la propriété est
analogue au verbe. Le choix de sens d'une propriété entre son domaine et sa cible est essentiellement arbitraire, de
même que pour une phrase le choix entre la voix active et la voix passive est arbitraire. Les noms de propriété dans le
CRM sont conçus pour être sémantiquement significatifs et grammaticalement corrects quand ils sont lus du domaine vers
la cible. De plus, le nom de propriété inverse, normalement donné entre parenthèses, est aussi conçu pour être
sémantiquement significatif et grammaticalement correct quand il est lu de la cible vers le domaine.
3.5
extension
l'ensemble de toutes les instances réelles d'une classe qui respectent les critères de son intension
NOTE 1 L'extension d'une classe est un ensemble «ouvert» dans le sens qu'il est, en général, impossible de connaître
toutes les instances d'une classe dans le monde; l'avenir peut créer de nouveaux cas à tout moment (dans un Monde
Ouvert). Un système d'information ne peut, à un moment donné, se référer qu'à certaines instances d'une classe, qui
forment un sous-ensemble de son extension.
NOTE 2 Voir aussi 5.6.
3.6
héritage
duplication des attributs d'une classe vers ses sous-classes
NOTE L'héritage de propriétés de super-classes vers les sous-classes signifie que si un terme x est une instance
d'une classe A, toutes les propriétés qui s'appliquent aux instances des super-classes de A s'appliquent également au
terme x et que toutes les propriétés facultatives qui s'appliquent aux super-classes de A s'appliquent également au terme x.
3.7
instance
terme dont les attributs correspondent aux critères de l'intension de la classe
NOTE «La Joconde» est une instance de la classe des «objets physiques fabriqués par l'homme». Une instance
d'une propriété est une relation factuelle entre une instance du domaine et une instance de la cible de la propriété qui
correspond aux critères de l'intension de la propriété. Par exemple, «le Louvre est le propriétaire actuel de La Joconde»
est une instance de la propriété «est le propriétaire actuel de». Le nombre d'instances d'une classe déclarées dans un
système d'information est normalement inférieur au total des instances réelles. Par exemple, vous êtes une instance de
«Personne», mais vous ne figurez pas dans tous les systèmes d'information qui décrivent des «Personnes».
© ISO 2006 – Tous droits réservés 3

---------------------- Page: 9 ----------------------
ISO 21127:2006(F)
3.8
intension
signification d'une classe
NOTE L'intension d'une classe consiste en un ou en plusieurs attributs communs partagés par toutes les instances
de la classe. Ces attributs n'ont pas besoin d'être explicitement formulés en termes logiques, mais peuvent simplement
être décrits dans un texte (une note d'application) qui se réfère à une conceptualisation commune aux experts de domaine.
3.9
interopérabilité
capacité des systèmes d'information à communiquer une partie de leur contenu
NOTE L'interopérabilité peut signifier que
a) deux systèmes peuvent échanger des informations, et/ou
b) des systèmes multiples peuvent être exploités par le biais d'une méthode unique.
En général, une distinction peut être faite entre l'interopérabilité syntactique et l'interopérabilité sémantique.
L'interopérabilité syntactique signifie que le codage de l'information des systèmes et les protocoles d'accès sont
compatibles; ainsi les informations peuvent être traitées comme décrit ci-dessus et sans erreurs. Cependant, ceci ne
garantit pas que chaque système traite les données de façon compatible avec la signification voulue. Par exemple un
système peut utiliser une table appelée «Acteur» et une autre appelée «Agent». À un niveau d'interopérabilité syntactique,
les deux tables sont traitées comme des entités distinctes, bien qu'au niveau sémantique elles puissent avoir exactement
la même signification. L'interopérabilité sémantique est également nécessaire pour surmonter le problème. Le CRM part
du principe que l'interopérabilité syntactique est assurée et s'occupe seulement de l'addition de l'interopérabilité
sémantique.
3.10
monotonique
〈d'une base de connaissances〉 ayant un ensemble de conclusions tirées par des règles d'inférence qui ne
diminue jamais, malgré l'addition de propositions supplémentaires
NOTE 1 Le raisonnement monotonique est un terme dérivé de la représentation des connaissances. En termes
pratiques, si des experts entrent des déclarations dans un système d'information, le système ne doit jamais considérer les
résultats de ces déclarations comme invalides lorsqu'une nouvelle déclaration est entrée. L'ontologie CRM est conçue
pour le raisonnement monotonique et permet la fusion sans conflits de grands fonds de connaissance.
NOTE 2 Voir aussi 5.1.
3.11
héritage multiple
possibilité pour une classe d'avoir plus d'une super-classe directe
NOTE L'extension d'une classe avec plusieurs super-classes directes est un sous-ensemble de l'intersection de
toutes les extensions de ses super-classes. L'intension d'une classe avec plusieurs super-classes directes multiples étend
l'intension de toutes ses super-classes, c'est-à-dire que ses attributs sont plus restrictifs que ceux de ses super-classes.
Si l'héritage multiple est utilisé, la «hiérarchie de classes» qui en résulte est un graphe dirigé et non pas une arborescence.
Si elle est représentée comme une liste indentée, il y a nécessairement des répétitions de la même classe à des positions
différentes dans la hiérarchie. Par exemple, «Personne» est à la fois un «Acteur» et un «Objet biologique».
3.12
monde ouvert
supposition que les informations stockées dans une base de connaissances sont incomplètes par rapport à
l'univers de discours qu'elle tente de décrire
NOTE Un terme dérivé de la représentation des connaissances. L'incomplétude d'une base peut être due à
l'incapacité du gestionnaire à fournir des informations suffisantes, ou à des problèmes plus fondamentaux de
connaissances dans le domaine du système. De tels problèmes sont caractéristiques de systèmes d'information culturels.
Nos archives relatives au passé sont nécessairement incomplètes. De plus, il peut exister des items qui ne peuvent pas
être assignés sans équivoque à une classe donnée. Plus spécifiquement, l'absence d'une certaine propriété pour un item
décrit par le système ne signifie pas forcément que l'item en question ne possède pas cette propriété. Par exemple, si un
article est décrit comme un Objet biologique et un autre comme un Objet matériel, ceci n'implique pas que ce dernier ne
soit pas également un Objet biologique. De façon générale, on ne peut donc pas déduire les compléments d'une classe
par rapport à une super-classe dans un système d'information basé sur la Supposition du Monde Ouvert.
4 © ISO 2006 – Tous droits réservés

---------------------- Page: 10 ----------------------
ISO 21127:2006(F)
3.13
concept primitif
concept qui peut être déclaré et dont la signification est connue, mais qui ne peut pas être dérivé à partir
d'autres concepts
NOTE Concept primitif est un terme dérivé de la représentation des connaissances. Par exemple mère peut se
décrire comme un être féminin ayant un enfant. Alors mère n'est pas un concept primitif. En revanche, Événement est un
concept primitif. Le CRM est composé, en majeure partie, de concepts primitifs.
3.14
propriété
caractéristique qui définit une relation de nature très spécifique entre deux classes
NOTE Une propriété est caractérisée par une intension, qui est présentée par une note d'application. Une propriété
joue un rôle analogue au verbe dans une phrase: elle est définie par référence à son domaine et à sa cible, qui sont
comparables au sujet et à l'objet d'une phrase (une classe, par distinction, peut être définie indépendamment). Le choix
de sens d'une propriété entre son domaine et sa cible est essentiellement arbitraire, de même que pour une phrase le
choix entre la voix active et la voix passive est arbitraire. Autrement dit, une propriété peut être interprétée dans les deux
sens, avec deux interprétations qui sont distinctes mais liées. Les propriétés peuvent elles
...