Metadata is often defined as "data about data". It is also known as data documentation. Metadata is used to describe and document research data. Metadata facilitates searching for data in an archive or repository, and makes the data easily understood by anyone who wants to use the data. It describes the who, what, when, where, how and why about data.
There are three types of metadata; descriptive, structural, and administrative.
Descriptive Metadata supports discovery and identification.
Examples: title, creator, unique identifiers, subjects, keywords
Structural Metadata describes how a resource is organized.
Examples: Manifest of files in a dataset, table of contents, or schema of database tables
Administrative Metadata helps in managing the resource by describing technical aspects, rights management, and preservation information.
Technical Examples: file type, version information, how/when created
Rights Management Examples: licensing, use restrictions, privacy concerns
Preservation Examples: ownership, history of use, authenticity
Best Practices for Creating Metadata
Vocabulary are concepts and terms in a domain.
Controlled Vocabulary indicate the same meaning for words. It is a closed prescribed list of terms.
Taxonomy is controlled vocabulary that is arranged in a hierarchy. Terms are not usually defined and relationships between terms are not defined.
Thesaurus is a taxonomy that contains additional information about the use of terms. Example: MeSH
Ontology is a controlled vocabulary that defines the terms in a given domain or knowledgebase, and the relationships between those terms. Example: SNOMED
Polysemy are terms that means more than one concept.
Example- Leads [Hypertension leads to heart disease, an EKG lead, Lead poisoning]
Synonyms are terms that mean the same thing.
Example- Common cold [cold, upper respiratory infection, URI, pharyngitis, viral syndrome, bronchitis, rhinitis]
Use Cases for Controlled Vocabularies: