metadatadatum

A metadatadatum is a singular unit of metadata that describes a resource. It is the atomic element within a metadata schema or record, consisting of a property name (such as title, creator, date, or format) and an associated value. A metadatadatum may also carry metadata about itself, including language, datatype, units, accuracy, provenance, or confidence.

In practice, metadatadata units are collected into a metadata record that describes various aspects of a resource. Many standards refer to these atomic units as metadata elements, data elements, or fields. The term metadatadatum emphasizes the singular nature of one descriptive piece within a broader metadata framework.

Examples illustrate typical metadatadata: in a catalog record, a metadatadatum might be the element "title" with the value "The Great Gatsby," or the element "date" with the value "1925-04-10" and datatype date. In a digital library, there may be metadatadata for format, language, subject, and rights. The values can be plain strings or constrained by controlled vocabularies and ontologies, sometimes with language tags or standardized identifiers.

Role and significance: metadatadata enables resource discovery, interoperability, provenance tracking, and quality control. By defining standardized names and value types, metadata systems support efficient search, data integration, and reuse across platforms. While the term metadatadatum is less common in everyday practice—where people often say metadata element or metadata field—the concept remains a foundational unit in metadata modeling.