This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help improve this article by introducing citations to additional sources.(July 2017)
A representation term is a word, or a combination of words, used as part of a data element name. Representation class is sometimes used as a synonym for representation term.
A representation term is a word, or a combination of words, that semantically represent the data type of a data element. A representation term is commonly referred to as a class word by those familiar with data dictionaries. ISO/IEC 11179-5:2005 defines representation term as a designation of an instance of a representation class As used in ISO/IEC 11179, the representation term is that part of a data element name that provides a semantic pointer to the underlying data type. A Representation class is a class of representations. This representation class provides a way to classify or group data elements.
A data element name is a name given to a data element in, for example, a data dictionary or metadata registry. In a formal data dictionary, there is often a requirement that no two data elements may have the same name, to allow the data element name to become an identifier, though some data dictionaries may provide ways to qualify the name in some way, for example by the application system or other context in which it occurs.
A synonym is a word or phrase that means exactly or nearly the same as another lexeme in the same language. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy. For example, the words begin, start, commence, and initiate are all synonyms of one another. Words are typically synonymous in one particular sense: for example, long and extended in the context long time or extended time are synonymous, but long cannot be used in the phrase extended family. Synonyms with the exact same meaning share a seme or denotational sememe, whereas those with inexactly similar meanings share a broader denotational or connotational sememe and thus overlap within a semantic field. The former are sometimes called cognitive synonyms and the latter, near-synonyms, plesionyms or poecilonyms.
In ISO/IEC 11179, a representation class provides a way to classify or group data elements. A representation class is effectively a specialized classification scheme. Hence, there is currently some discussion in ISO over the merits of keeping representation class as a separate entity in 11179, versus collapsing it into the general classification scheme facility. A clear distinction between the two mechanisms, however, is that 11179 allows a data element to be classified by only one representation class, whereas there is no such restriction on other classification schemes.
ISO/IEC 11179 is an international standard for representing metadata for an organization in a metadata registry.
ISO/IEC 11179 does not specify that representation terms should be drawn from the values of representation class, though it would make sense to do so, nor does it provide any mechanism to ensure any sort of consistency (whatever that might mean) between the representation terms used to name a data element, and the representation class used to classify it.
The term representation class has been used in metadata registry standards for many years. Today it has a combination of meanings and now goes well beyond how a data element is represented in a computer system. In practice this term is used to shed light on the semantics or meaning of the data element.
Semantics is the linguistic and philosophical study of meaning, in language, programming languages, formal logics, and semiotics. It is concerned with the relationship between signifiers—like words, phrases, signs, and symbols—and what they stand for in reality, their denotation.
Definitions of "representation class"
There are several alternate definitions for representation class. Some of these are taken from the ISO documents. Note that these documents are copyrighted and extracts can only be taken under the fair use rules.
ISO Definitions of representation class
From ISO/IEC TR 20943-1 First edition 2003-08-01 pdf page 91
B.2.3 Representation class
Representation class is the value domain for representation. The set of classes make it easy to distinguish among the elements in the registry. For instance, a data element categorized with the representation class amount is different from an element categorized as number. It probably will not make sense to compare the contents of these elements, or perform calculations using them together.
Representation class is a mechanism by which the functional and/or presentational category of an item may be conveyed to the user.
From ISO/IEC 11179-3 Second edition 2003-02-15
3.3.51 data element representation class the class of representation of a data element
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
Related Research Articles
The Dublin Core Schema is a small set of vocabulary terms that can be used to describe digital resources, as well as physical resources such as books or CDs, and objects like artworks. The full set of Dublin Core metadata terms can be found on the Dublin Core Metadata Initiative (DCMI) website. The original set of 15 classic metadata terms, known as the Dublin Core Metadata Element Set (DCMES), is endorsed in the following standards documents:
A metadata registry is a central location in an organization where metadata definitions are stored and maintained in a controlled method.
The Universal Data Element Framework (UDEF) was a controlled vocabulary developed by The Open Group. It provided a framework for categorizing, naming, and indexing data. It assigned to every item of data a structured alphanumeric tag plus a controlled vocabulary name that describes the meaning of the data. This allowed relating data elements to similar elements defined by other organizations.
In metadata, a data element definition is a human readable phrase or sentence associated with a data element within a data dictionary that describes the meaning or semantics of a data element.
Semantic translation is the process of using semantic information to aid in the translation of data in one representation or data model to another representation or data model. Semantic translation takes advantage of semantics that associate meaning with individual data elements in one dictionary to create an equivalent meaning in a second system.
Metadata publishing is the process of making metadata data elements available to external users, both people and machines using a formal review process and a commitment to change control processes.
The Extended Metadata Registry (XMDR) is a project proposing and testing a set of extensions to the ISO/IEC 11179 metadata registry specifications that deal with the development of improved standards and technology for storing and retrieving the semantics of data elements, terminologies, and concept structures in metadata registries.
In metadata an indicator is a Boolean value that may contain only the values true or false. The definition of an Indicator must include the meaning of a true value and should also include the meaning if the value is false.
A classification scheme is the product of arranging things into kinds of things (classes) or into groups of classes.
Digital Item is the basic unit of transaction in the MPEG-21 framework. It is a structured digital object, including a standard representation, identification and metadata.
The Open Packaging Conventions (OPC) is a container-file technology initially created by Microsoft to store a combination of XML and non-XML files that together form a single entity such as an Open XML Paper Specification (OpenXPS) document. OPC-based file formats combine the advantages of leaving the independent file entities embedded in the document intact and resulting in much smaller files compared to normal use of XML.
Metadata is "data [information] that provides information about other data". Many distinct types of metadata exist, among these descriptive metadata, structural metadata, administrative metadata, reference metadata and statistical metadata.
A metadata standard is a requirement which is intended to establish a common understanding of the meaning or semantics of the data, to ensure correct and proper use and interpretation of the data by its owners and users. To achieve this common understanding, a number of characteristics, or attributes of the data have to be defined, also known as metadata.
ISO/IEC 19788Information technology – Learning, education and training – Metadata for learning resources is a multi-part standard prepared by subcommittee SC36 of the Joint Technical Committee ISO/IEC JTC1, Information Technology for Learning, Education and Training.
This committee was created to deal with the consequences of substantial overlap in areas of standardization done at the International Organization for Standardization (ISO) and the International Electrotechnical Commission.
The Aristotle Metadata Registry is an open-source Metadata Registry framework based on the ISO/IEC 11179 standard for Metadata Registries. It is influenced by the AIHW Meteor Metadata Registry and the Canadian Institute of Health Information Indicator Bank. Aristotle-MDR is designed to describe data holdings databases and associated structural metadata. The Aristotle Metadata Registry was publicly launched at the 2015 IASSIST Conference in Toronto. In 2016, the founders of the Aristotle Metadata Registry were hired by Data61 to continue development of the platform.
IEC Common Data Dictionary is a metadata registry based on the data model defined in IEC 61360-2/ISO 13584-42 with an enhancement of its modelling capability adopted from IEC 62656-1. The description of the data model for dictionary developers in particular for those in electrotechnical domains is given in IEC 61360-1. Currently the scope of the registry is extended to cover all ISO and IEC domains, thus it is no longer "IEC CDD", nevertheless it is hosted by IEC-CO and is maintained by IEC SC 3D with a joint working group formed between IEC SC 3D and ISO TC 184/SC4. The data model of the CDD references ISO/IEC 11179 for the identification of the registered elements. It is used to host product classifications. - This means the IEC CDD is a database providing classifications and metadata definitions for describing products. The IEC CDD is an International Standard in the form of an online database, not in the form of (e-)paper, and is given the standard number IEC 61360-4 DB. Thus the metadata registered into the database has the status of International Standard. The procedure to add a new definition or a set of definitions is based on the IEC database procedure, described in Annex SL of the IEC supplementary of the ISO/IEC directive Part 1. This process for updating the content is called a "Change Request" and when a Change Request is issued and adopted, the proposed item will become part of the International Standard, IEC 61360-4 DB, within approximately 6 months.
