Classification scheme
Encyclopedia
In metadata
a classification scheme is a hierarchical arrangement of kinds of things (classes) or groups of kinds of things. Typically it is accompanied by descriptive information of the classes or groups. A classification scheme is intended to be used for an arrangement or division of individual objects into the classes or groups. The classes or groups are based on characteristics which the objects (members) have in common. In linguistics
, the subordinate concept is called a hyponym of its superordinate. Typically a hyponym is 'a kind of' its superordinate (Keith Allan, Natural language Semantics).
The ISO/IEC 11179
metadata registry standard uses classification schemes as a way to classify administered items, such as data element
s, in a metadata registry
.
Some quality criteria for classification schemes are:
One example of a classification scheme for data element
s is a representation term
.
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
a classification scheme is a hierarchical arrangement of kinds of things (classes) or groups of kinds of things. Typically it is accompanied by descriptive information of the classes or groups. A classification scheme is intended to be used for an arrangement or division of individual objects into the classes or groups. The classes or groups are based on characteristics which the objects (members) have in common. In linguistics
Linguistics
Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....
, the subordinate concept is called a hyponym of its superordinate. Typically a hyponym is 'a kind of' its superordinate (Keith Allan, Natural language Semantics).
The ISO/IEC 11179
ISO/IEC 11179
ISO/IEC 11179 is an international standard for representing metadata for an organization in a metadata registry.- Intended purpose :...
metadata registry standard uses classification schemes as a way to classify administered items, such as data element
Data element
In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has:# An identification such as a data element name# A clear data element definition# One or more representation terms...
s, in a metadata registry
Metadata registry
A metadata registry is a central location in an organization where metadata definitions are stored and maintained in a controlled method.-Use of Metadata Registries:...
.
Some quality criteria for classification schemes are:
- Whether different kinds are grouped together. In other words whether it is a grouping system or a pure classification system. In case of grouping, a subset (subgroup) does not have (inherit) all the characteristics of the superset, which makes that the knowledge and requirements about the superset are not applicable for the members of the subset.
- Whether the classes have overlaps.
- Whether subordinates (may) have multiple superordinates. Some classification schemes allow that a kind of thing has more than one superordinate others don't. Multiple supertypes for one subtype implies that the subordinate has the combined characteristics of all its superordinates. This is called multiple inheritance (of characteristics from multiple superordinates to their subordinates).
- Whether the criteria for belonging to a class or group are well defined.
- Whether the kinds of relations between the concepts are made explicit and well defined.
- Whether subtype-supertype relations are distinguished from composition relations (part-whole relations) and from object-role relations.
Benefits of using classification schemes
Using one or more classification schemes for the classification of a collection of objects has many benefits. Some of these include:- It allows a user to find an individual object quickly on the basis of its kind or group.
- It makes it easier to detect duplicate objects.
- It conveys semanticsSemanticsSemantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....
(meaning) of an object from the definition of its kind, which meaning is not conveyed by the name of the individual object or its way of spelling. - Knowledge and requirements about a kind of thing can be applied to the members of the kind.
Examples of kinds of classification schemes
The following are examples of different kinds of classification schemes. This list is in approximate order from informal to more formal:- thesaurusThesaurusA thesaurus is a reference work that lists words grouped together according to similarity of meaning , in contrast to a dictionary, which contains definitions and pronunciations...
- a collection of categorized concepts, denoted by words or phrases, that are related to each other by narrower term, wider term and related term relations. - taxonomyTaxonomyTaxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
- a formal list of concepts, denoted by controlled words or phrases, arranged from abstract to specific, related by subtype-supertype relations or by superset-subset relations. - data modelData modelA data model in software engineering is an abstract model, that documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data is stored and accessed....
- an arrangement of concepts (entity types), denoted by words or phrases, that have various kinds of relationships. Typically, but not necessarily, representing requirements and capabilities for a specific scope (application area). - network (mathematics) - an arrangement of objects in a random graph.
- ontologyOntology (computer science)In computer science and information science, an ontology formally represents knowledge as a set of concepts within a domain, and the relationships between those concepts. It can be used to reason about the entities within that domain and may be used to describe the domain.In theory, an ontology is...
- an arrangement of concepts that are related by various well defined kinds of relations. The arrangement can be visualized in a directed acyclic graph.
One example of a classification scheme for data element
Data element
In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has:# An identification such as a data element name# A clear data element definition# One or more representation terms...
s is a representation term
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...
.
See also
- ISO/IEC 11179ISO/IEC 11179ISO/IEC 11179 is an international standard for representing metadata for an organization in a metadata registry.- Intended purpose :...
- MetadataMetadataThe term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
- Ontology (computer science)Ontology (computer science)In computer science and information science, an ontology formally represents knowledge as a set of concepts within a domain, and the relationships between those concepts. It can be used to reason about the entities within that domain and may be used to describe the domain.In theory, an ontology is...
- Simple Knowledge Organisation System
- Representation classRepresentation classA 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....
- Representation termRepresentation termA 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...
- Semantic spectrumSemantic spectrumThe semantic spectrum is a series of increasingly precise or rather semantically expressive definitions for data elements in knowledge representations, especially for machine use.At the low end of the spectrum is a simple binding of a single word or phrase and its...