1、 Reference numberISO/IEC 11179-4:2004(E)ISO/IEC 2004INTERNATIONAL STANDARD ISO/IEC11179-4Second edition2004-07-15Information technology Metadata registries (MDR) Part 4: Formulation of data definitions Technologies de linformation Registres de mtadonnes (RM) Partie 4: Formulation des dfinitions de d
2、onnes Adopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 12/29/2004Published by American National Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2004 by Information Technology Industry C
3、ouncil (ITI).All rights reserved.These materials are subject to copyright claims of International Standardization Organization (ISO), InternationalElectrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council(ITI). Not for resale. No par
4、t of this publication may be reproduced in any form, including an electronic retrieval system, withoutthe prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaISO/IEC 11179
5、-4:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes 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
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8、low. ISO/IEC 2004 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 ISOs member
9、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 copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2004 All rights reservedISO/IEC 11179-4:2004(E) ISO/IEC 2004 All rights reserved iiiCo
10、ntents Page Foreword iv Introduction v 1 Scope 1 2 Conformance . 1 3 Terms and definitions. 1 4 Summary of data definition requirements and recommendations 3 4.1 Requirements 3 4.2 Recommendations 3 5 Provisions 4 5.1 Premises 4 5.2 Requirements 4 5.3 Recommendations 6 Bibliography . 9 ISO/IEC 11179
11、-4:2004(E) iv ISO/IEC 2004 All rights reservedForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the develop
12、ment of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmenta
13、l, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the
14、joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Att
15、ention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. ISO/IEC 11179-4 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
16、 Subcommittee SC 32, Data management and interchange. This second edition cancels and replaces the first edition (ISO/IEC 11179-4:1995), which has been technically revised. ISO/IEC 11179 consists of the following parts, under the general title Information technology Metadata registries (MDR): Part 1
17、: Framework Part 3: Registry metamodel and basic attributes Part 4: Formulation of data definitions Part 5: Naming and identification principles Part 6: Registration The following part is under preparation: Part 2: Classification ISO/IEC 11179-4:2004(E) ISO/IEC 2004 All rights reserved vIntroduction
18、 Data processing and electronic data interchange rely heavily on accurate, reliable, controllable and verifiable data recorded in databases. A prerequisite for correct and proper use and interpretation of data is that both users and owners of data have a common understanding of the meaning and repre
19、sentation of the data. To facilitate this common understanding, a number of characteristics, or attributes of the data have to be defined. These characteristics of data are known as “metadata”, that is, “data that describes data”. This part of ISO/IEC 11179 specifies requirements and recommendations
20、 on the formulation of data definitions that are specified in Metadata Registries. The purpose of these definitions is to specify, describe, explain, and clarify the meaning of data, to promote the standardization or reuse of data elements, and to promote data sharing and integration of information
21、systems. The structure of a Metadata Registry is specified in the form of a conceptual data model. The Metadata Registry is used to keep information about data elements and associated concepts, such as “data element concepts”, “conceptual domains”, and “value domains”. Generically, these are all ref
22、erred to as “metadata items”. Such metadata are necessary to clearly describe, record, analyse, classify, and administer data. The definitional requirements and recommendations specified in this part of ISO/IEC 11179 do not always apply to terminological definitions found in glossaries and language
23、dictionaries. Differences exist between the requirements that apply in a language dictionary, and the requirements that apply in a metadata registry. The requirements for ISO/IEC 11179 are more restrictive than those for a natural language dictionary. For example, a language dictionary may have mult
24、iple definitions covering multiple senses of a term or word, whereas data definitions are developed for particular contexts and should not have multiple senses within any context. Data definitions are intended to explicate the concept or concepts, which are represented by a collection of data, a dat
25、a value, a data element, or other metadata item. A single definition may be established as the reference definition, with other definitions asserted to be equivalent (e.g., a definition in one language may be established as a reference definition, with definitions in other languages asserted to be e
26、quivalent). Metadata items may have a single preferred definition within a particular context, with other deprecated definitions. Many data definitions include terms that themselves need to be defined (e.g., “charge”, “allowance”, “delivery”). Some of these terms may have different definitions in di
27、fferent industrial sectors. Therefore, there is a need for most metadata registries to establish an associated glossary or terminology reference of terms used in the definitions. INTERNATIONAL STANDARD ISO/IEC 11179-4:2004(E) ISO/IEC 2004 All rights reserved 1Information technology Metadata registri
28、es (MDR) Part 4: Formulation of data definitions 1 Scope This part of ISO/IEC 11179 specifies requirements and recommendations for constructing definitions for data and metadata. Only semantic aspects of definitions are addressed; specifications for formatting the definitions are deemed unnecessary
29、for the purposes of ISO/IEC 11179. While especially applicable to the content of metadata registries as specified in ISO/IEC 11179-3, this part of ISO/IEC 11179 is useful broadly for developing definitions for data and metadata. These definitional requirements and recommendations pertain to formulat
30、ing definitions for data elements and other types of data constructs such as entity types, entities, relationships, attributes, object types (or classes), objects, composites, code entries, metadata items, and the data referred to by XML tags. 2 Conformance This part of ISO/IEC 11179 may be used ind
31、ependently, e.g., for defining data elements outside the context of a metadata registry. In such cases, compliance may be claimed if the requirements and recommendations have been followed in developing the definitions. Where used in the context of an ISO/IEC 11179 metadata registry, this part of IS
32、O/IEC 11179 shall constitute the criteria for definitions when establishing the registration status as specified in ISO/IEC 11179-6. 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 Conceptual Domain set of valid value meanings NOTE The value
33、meanings may either be enumerated or expressed via a description. ISO/IEC 11179-3:2003, 3.3.21 3.2 Concept unit of knowledge created by a unique combination of characteristics ISO 1087-1:2000, 3.2.1 3.3 data re-interpretable representation of information in a formalized manner suitable for communica
34、tion, interpretation or processing NOTE Data can be processed by human or automatic means. ISO/IEC 2382-1:1993, 01.01.02 ISO/IEC 11179-4:2004(E) 2 ISO/IEC 2004 All rights reserved3.4 data element unit of data for which the definition, identification, representation and permissible values are specifi
35、ed by means of a set of attributes ISO/IEC 11179-3:2003, 3.3.36 3.5 Data Element Concept concept that can be represented in the form of a data element, described independently of any particular representation ISO/IEC 11179-3:2003, 3.3.38 3.6 definition representation of a concept by a descriptive st
36、atement which serves to differentiate it from related concepts ISO 1087-1:2000, 3.3.1 3.7 metadata data that defines and describes other data ISO 1087-1:2000, 3.2.18 3.8 Metadata Registry information system for registering metadata ISO/IEC 11179-3:2003, 3.2.22 3.9 metadata item instance of a metadat
37、a object NOTE 1 In all parts of ISO/IEC 11179, this term is applied only to instances of metadata objects described by the metamodel in Clause 4 of ISO/IEC 11179-3:2003. Examples include instances of data elements, data element concepts, permissible values, etc. NOTE 2 A metadata item has associated
38、 attributes, as appropriate for the metadata object it instantiates. ISO/IEC 11179-3:2003, 3.2.19 3.10 metadata object object type defined by a metamodel NOTE In all parts of ISO/IEC 11179, this term is applied only to metadata objects described by the metamodel in Clause 4 of ISO/IEC 11179-3:2003.
39、Examples include data elements, data element concepts, permissible values etc. See Clause 3.3 of ISO/IEC 11179-3:2003 for a complete list. ISO/IEC 11179-3:2003, 3.2.20 3.11 name designation of an object by a linguistic expression ISO/IEC 11179-3:2003, 3.2.26 ISO/IEC 11179-4:2004(E) ISO/IEC 2004 All
40、rights reserved 33.12 Value Domain set of permissible values NOTE 1 The value domain provides representation, but has no implication as to what data element concept the values may be associated with nor what the values mean. NOTE 2 The permissible values may either be enumerated or expressed via a d
41、escription. ISO/IEC 11179-3:2003, 3.3.140 4 Summary of data definition requirements and recommendations A listing of the requirements and recommendations without explanations is provided in this clause for convenience of the user. The intent is to facilitate ease of use of this document once an unde
42、rstanding of the requirements and recommendations is achieved. Clause 5 describes each requirement and recommendation with an explanation and examples to ensure their exact meaning is understood. 4.1 Requirements A data definition shall: a) be stated in the singular b) state what the concept is, not
43、 only what it is not c) be stated as a descriptive phrase or sentence(s) d) contain only commonly understood abbreviations e) be expressed without embedding definitions of other data or underlying concepts 4.2 Recommendations A data definition should: a) state the essential meaning of the concept b)
44、 be precise and unambiguous c) be concise d) be able to stand alone e) be expressed without embedding rationale, functional usage, or procedural information f) avoid circular reasoning g) use the same terminology and consistent logical structure for related definitions h) be appropriate for the type
45、 of metadata item being defined ISO/IEC 11179-4:2004(E) 4 ISO/IEC 2004 All rights reserved5 Provisions 5.1 Premises Data is used for specific purposes. Differences in use require different operational manifestations of some requirements and recommendations. For example, different levels of specifici
46、ty for data definitions are generally required in different contexts. Recommendation 5.3.a) below, provides an example of this need for varying levels of specificity for different definitions. The implementation of Recommendation 5.3.a), “state the essential meaning of the concept” is context depend
47、ent. The primary characteristics deemed necessary to convey the essential meaning of a particular definition will vary according to the level of generalization or specialization of the data. Primary and essential characteristics for defining concepts such as “airport” in the commercial air transport
48、ation industry might be specific, where a more general definition may be adequate in a different context. Within a metadata registry, multiple equivalent definitions may be written in different languages or, within a single language, for different audiences such as children, general public, or subje
49、ct area specialists. For a discussion of relationships between concepts in different contexts and how characteristics are used to differentiate concepts, see ISO 704, Clause 5. Definitions should be written to facilitate understanding by any user and by recipients of shared data. 5.2 Requirements To facilitate understanding of the requirements for construction of well-formed data definitions, explanations and examples are provided below. Each requirement is followed by a short explanation of its mea
