Thesaurus categories

Characteristics of thesauri, including general subjects such as place or theme, and structural or functional characteristics such as hierarchy and transitivity.

(subjects)

Distinct segments of human knowledge, such as place, time, or theme.

place

Terms indicate extent in space, typically by reference as the names of geographic areas known from information that is stored elsewhere. (use for geography, geospatial, spatial)

theme

Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things. (use for subject, topic)

biological taxonomy

Terms indicate groups of organisms identified by names where the rules governing the specification and use of the names are defined by well known tradition or by governing bodies such as international commissions. (use for systematics, taxa, taxon)

lithology

Rock types; may be further divided by composition, texture, mode of formation, or physical form of the rock body. (use for rock types)

stratum

Terms indicating packages of earth materials that have a common characteristic such as age, composition, mode of formation or deformation.

temporal

Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons. (use for seasons, time, time periods)

organizations

Terms specify human organizations, their subdivisions and relationships, as well as characteristics of such organizations.

persons

Terms specify individual people, typically by name. (use for people)

organizational functions

Things that organizations do, typically including various types of programs, projects, and services.

methods

Actions taken to obtain or analyze information (use for techniques)

disciplines

Broad categories of human inquiry or activity, such as scientific disciplines. (use for fields of study)

information representation

Terms indicating the content, format, or packaging of information that may be available.

information product types

Terms categorizing information products by the content, intended use or audience, or formality.

information format

Terms indicating the format in which information is made available. (use for data format)

(structure and function)

Characteristics of vocabularies like hierarchy, transitivity, granularity that might be used by automated processes to make decisions.

(hierarchy)

Terms are arranged with broader and narrower relationships specified explicitly.

flat

The vocabulary consists of a list of terms that are of roughly equal generality. This applies also in the case where a single broader term serves as parent to the entire vocabulary.

hierarchical

Substantive broader-narrower relationships exist among the terms. (use for hierarchial)

polyhierarchical

Terms are arranged in hierarchy and some terms may have more than one broader term.

pseudohierarchical

Broader-narrower relationships exist in the vocabulary but have no semantic relation to the terms themselves, for example, a list of peoples' names arranged hierarchically by the first letter of the surname.

(transitivity)

Hierarchical relationships may be intentionally transitive or not transitive; automated processes may use this characteristic to compose collections of relevant documents indexed using the vocabulary.

transitive

Narrower terms have an "is a" relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term.

not transitive

Narrower terms cannot reliably be understood as parts of, types of, or instances of the terms that are broader than them.

(generality)

Nature of the terms: types or instances

types

Terms are types of things rather than named instances

instances

Terms are named instances of things rather than types

distinct labels

Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor.

ambiguous labels

A given preferred label may be used for more than one concept in the thesaurus. A concept must be specified using its unique identifier (code). This may occur in the names of places or people.