ISO/IEC TR 20943-5:2013

TECHNICAL ISO/IEC
REPORT TR
20943-5
First edition
2013-11-01
Information technology — Procedures
for achieving metadata registry
content consistency —
Part 5:
Metadata mapping procedure
Technologies de l’information — Procédures pour réaliser la
consistance du contenu de l’enregistrement des métadonnées —
Partie 5: Procédure de mappage des métadonnées
Reference number
ISO/IEC TR 20943-5:2013(E)
©
ISO/IEC 2013

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ISO/IEC TR 20943-5:2013(E)

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ISO/IEC TR 20943-5:2013(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 Metadata mapping procedure . 3
5.1 Overview . 3
5.2 Data element concept mapping . 3
5.3 Conceptual domain mapping . 7
Annex A (informative) Relationship between metadata mapping and registry.9
Annex B (informative) Factoring and types of heterogeneity .10
Bibliography .13
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ISO/IEC TR 20943-5:2013(E)

Foreword
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 development 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-governmental, 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 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.
In exceptional circumstances, when the joint technical committee has collected data of a different kind
from that which is normally published as an International Standard (“state of the art”, for example), it
may decide to publish a Technical Report. A Technical Report is entirely informative in nature and shall
be subject to review every five years in the same manner as an International Standard.
Attention 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 TR 20943-5 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 32, Data management and interchange.
ISO/IEC TR 20943 consists of the following parts, under the general title Information technology —
Procedures for achieving metadata registry content consistency:
— Part 1: Data elements
— Part 3: Value domains
— Part 5: Metadata mapping procedure
— Part 6: Framework for generating ontologies
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ISO/IEC TR 20943-5:2013(E)

Introduction
Metadata differs in many ways, yet for the purposes of data and semantic interoperability, those
differences must be bridged or harmonized. For example, synonyms may cause discrepancies. If two
data elements mean the same thing but have different names, that difference may cause data under each
to be flagged as incompatible when they aren’t.
Usually, two systems do not share the same model, and that is because the categories represented in the
models were not factored in the same way. This situation inhibits interoperability. There may be two
or more metadata element sets applicable to an information object. For example, metadata schemas,
[10] [11]
such as DC (Dublin Core), MARC (MAchine Readable Cataloguing), and MODS (Metadata Object
[12]
Description Schema) can be used to describe books. So, the result might be significantly different
data elements in different schemas, even though the schemas describe the same objects.
ISO/IEC 11179 provides a framework for achieving interoperability of metadata between systems.
A metadata registry based on ISO/IEC 11179 offers a good way to secure interoperability among
databases. However, there are many metadata sets which are not following ISO/IEC 11179. In order
to mediate among plural data elements already developed or used, other measures are necessary. In
general, interoperability may be achieved through conformity to some set of provisions. For example,
metadata crosswalk is the most commonly used way to map a data element to another data element.
However, the metadata crosswalk is meaningful only for exact matching; it provides a simple one-to-one
mapping table between data elements without any explanation about the relationship. Therefore, the
metadata crosswalk needs to be elaborated in order to cover cases other than exact matching.
Some other approaches have been tried to provide guidelines or a model for harmonization of metadata
and data in especially the transport industry. A Model for Semantic Equivalence Discovery for
[9]
Harmonizing Master Data, presented at OTM 2009 Workshops, suggests a model for semantic mapping
[8]
of master data. ISO/TR 25100 reviews four harmonization processes applicable to an ITS/TICS central
data registry and ITS/TICS data dictionaries and recommends practical guidelines. Both literatures are
examples restricted within the transport industry but including a rationale for the need of metadata
mapping in general.
This part of ISO/IEC TR 20943 describes a metadata mapping procedure (MMP), which can maximize
the interoperability among metadata.
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TECHNICAL REPORT ISO/IEC TR 20943-5:2013(E)
Information technology — Procedures for achieving
metadata registry content consistency —
Part 5:
Metadata mapping procedure
1 Scope
The purpose of this part of ISO/IEC TR 20943 is to describe a procedure for establishing metadata crosswalks
based on the ISO/IEC 11179 series, subsequently improving mapping quality between metadata.
Therefore, this part of ISO/IEC TR 20943 describes a metadata mapping procedure (MMP), which can
maximize the interoperability among ISO/IEC 11179-based registries through achieving metadata
registry content consistency.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 11179-1:2004, Information technology — Metadata registries (MDR) — Part 1: Framework
ISO/IEC 11179-3:2013, Information technology — Metadata registries (MDR) — Part 3: Registry metamodel
and basic attributes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 11179 and the following apply.
3.1
crosswalk
mapping (3.8) of the elements, semantics, and syntax from one metadata scheme to those of another
[15]
Note 1 to entry: Definition taken from Understanding Metadata, 2004, NISO Press.
3.2
complicated difference
type of heterogeneity (3.4) that cannot be harmonized
3.3
domain difference
type of heterogeneity (3.4) arising from different kinds of contexts or cultures
3.4
heterogeneity
difference arising from different descriptions of the same concept
3.5
hierarchical difference
type of heterogeneity (3.4) arising from the different levels of details
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ISO/IEC TR 20943-5:2013(E)

3.6
interoperability
ability of multiple systems with different hardware and software platforms, data structures, and
interfaces to exchange data with minimal loss of content and functionality
[15]
Note 1 to entry: Definition taken from Understanding Metadata, 2004, NISO Press.
3.7
lexical difference
type of heterogeneity (3.4) arising from different designations
[SOURCE: ISO 1087-1:2000, 3.4.1]
3.8
mapping
correspondence between instances of one model and instances of another model that represent the
same meaning
[SOURCE: ISO/TS 18876-1:2003, 3.1.14]
3.9
metadata element set
small and fundamental group of data elements or data element concepts through which resources can
be described and catalogued in a domain
EXAMPLE DC (Dublin Core), MARC (MAchine Readable Cataloguing), MODS (Metadata Object Description
Schema), etc.
3.10
primary metadata element set
metadata element set (3.9) to which other metadata element sets are grouped
3.11
secondary metadata element set
metadata element set (3.9) which are grouped according to the primary metadata element set (3.10)
3.12
syntactic difference
type of heterogeneity (3.4) arising from varying arrangement of parts
4 Abbreviated terms
DC Dublin Core
DCMI Dublin Core Metadata Initiative
DE Data Element
DEC Data Element Concept
MARC MAchine Readable Cataloguing
MDR MetaData Registry
MMP Metadata Mapping Procedure
MODS Metadata Object Description Schema
NISO National Information Standards Organization (NISO is a USA organization: www.niso.org)
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ISO/IEC TR 20943-5:2013(E)

OEBPS Open EBook Publication Structure
TEI Text Encoding Initiative
5 Metadata mapping procedure
5.1 Overview
This part of ISO/IEC TR 20943 covers data element concept mapping and conceptual domain mapping.
The mapping procedure for data element concept, described in this part of ISO/IEC TR 20943, is
applicable to data element mapping, while the mapping procedure for conceptual domain includes value
domain mapping.
5.2 Data element concept mapping
5.2.1 Overview
The procedure for data element concept mapping consists of three main processes as shown in Figure 1.
Identifying metadata element sets
Grouping data element concepts
Mapping data element concepts

Figure 1 — Procedure for data element concept mapping
The first process is to identify metadata element sets required to be mapped. It is necessary to survey
available metadata element sets (in a specific domain).
The second process is to group data element concepts obtained from the identified metadata element
sets. This includes four consecutive sub-processes: finding object classes, grouping all data element
concepts by object class, finding their properties, and grouping all data element concepts by property.
The last process involves mapping data element concepts. In this process, it is necessary to arrange all
data element concepts into a table. Notes on the type of mapping are included in every slot of the table.
Figure 2 shows all sub-processes related to corresponding main processes.
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ISO/IEC TR 20943-5:2013(E)

MainProcesses Sub-Processes
1. Identifying metadata element sets to be
Identifying metadata element sets
mapped
2. Finding object classes of candidate metadata
element sets
Grouping data element concepts
3. Grouping data element concepts by object
classes
4. Finding properties
5. Grouping data element concepts by property
6. Finding common data element concepts
7. Mapping by common data element concept
Mapping data element concepts
8. Giving notes according to types of
heterogeneity


Figure 2 — Main and sub-processes for data element concept mapping
5.2.2 Identifying metadata element sets (First process)
5.2.2.1 Method
First, it is necessary to collect available metadata element sets and to identify candidate metadata
element sets to be mapped. Then, what the purpose of the metadata element set is should be checked,
how many numbers of fields should be counted, and whether sample data exists or not should be checked.
Who or which organization has the authority over each metadata element set should also be checked.
5.2.2.2 Examples
— Domain: e-book cataloguing
[13] [10] [12] [14]
— Available metadata element sets: OEBPS, DC, MODS and TEI
Table 1 — Analysing available metadata element sets
Metadata element
DC OEBPS MODS TEI header
set name
Encoding methods
Description of inter- Description of elec- Description of
Purpose for machine-readable
net resource tronic book library resources
texts
Number of fields 15 15 About 60 Over 20
Sample data yes yes No Yes
Authority DCMI Open eBook Forum Library of Congress TEI Consortium
5.2.3 Grouping data element concepts (Second process)
5.2.3.1 Method
The next process is to group data element concepts by object class, and then to find properties associated
with the objects and sub-group the data element concepts by property.
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For convenience, it is helpful to select a primary metadata element set among the candidate metadata
element sets and aggregate them by the primary metadata element set. The metadata element set having
the least number of elements is recommended to be the primary metadata element set.
All data element concepts included in the candidate metadata element sets should be aggregated by
property. Some data elements, which cannot be grouped, are supposed to be set aside.
In this process, metadata experts should perform the work along with domain experts.
5.2.3.2 Examples
In the sample object class, the e-book has plural properties as shown below.
— Object class: e-book
— Properties: title, author, subject, …, edition
Table 2 — Example of grouping data element concepts by property
Primary meta-
data element Secondary metadata element set
set
DC OEBPS MODS TEI
Title Title Title title
subTitle seriesStmt:title
partNumber seriesStmt:idno
partName
nonSort
Creator Creator(role) name:role author
Creator(file-as) name:namePart
nam
...