Index

Metadata

Metadata describe other data using information that is useful for interpreting and (automatically) processing the actual data, for example digital research data; they represent “data about data”.

Metadata can be elementary descriptions such as length, coding and type (number, string, date and time, currency amount, etc.). Much more important are metadata which help to categorize and characterize the properties of digital objects and provide further information that says something about their meaning. For measured values in research data, these are, for example: measuring device used or sensor used, accuracy or location of the measurement. Even the name of a data object says something about its meaning, but usually this is not enough. Often these terms are too short and too general (such as “measurement”). It’s only usually clear what this means in the context the data are used. In this way, research projects develop terms that can be misunderstood outside the project.

Ontologies are intended to relate such specific terms to a general system of terms.

There are different categories of metadata:

  • Technical metadata give information about the data volume and data format and are essential for saving data in the long term.
  • Descriptive metadata (also known as content metadata) give information about the information contained in the digital objects and therefore are decisive for the findability, referencing and reusability of data. Descriptions of the measuring method used, an abstract or keywords all fall into this category. Structural metadata describe relationships between individual elements of a data set or the internal structure of the data themselves.
  • Administrative metadata include information required for assuring the quality of data (for example checksum), and information on access rights and licenses or the provenance of the data.