What is metadata?
- Metadata means "data about data".
- Metadata is information about an object or resource that describes characteristics such as content, quality, format, location and contact information.
- It can be used to describe physical items as well as digital items (documents, audio-visual files, images, datasets, etc.).
- Metadata can take many different forms, from free text (such as read-me files) to standardized, structured, machine-readable content.
- Basics of metadata (video, 8.10mins) from meta|morphosis: film-to-digital tutorials.
Types of metadata
Metadata elements can describe either a single item or a collection, and can serve different purposes. Examples of metadata for a photograph could include:
- descriptive metadata, such as the name of the photographer, the location and subject of the photograph, the date and time that the photograph was taken
- technical metadata, such as the type of camera used to take the photograph, the file format in which the photograph is stored, the exposure time and dimensions of the photograph, and so on
- access and rights metadata, defining who is allowed to view the photograph under what conditions, and what they can do with it (reuse)
- preservation metadata, which keeps track of actions taken to preserve or sustain the photograph for later access and use.
Where does metadata come from?
- Metadata can be created manually by people or automatically by instruments or computers.
- Metadata capture is easiest if it is automatically generated when the data is created, for example, the metadata your camera captures every time you take a photo.
- For much research data, the researcher needs to create the descriptive and provenance metadata, as only they have that information.
Where is metadata stored?
- Metadata can be stored in local source systems with the data it is about, or in data or metadata stores.
- Metadata that enables research data to be discovered and accessed should be published in Research Data Australia, or in discipline or institutional portals.
- Metadata that gives detailed contextual information and supports reuse, such as data-item-level metadata, workflows, analysis, and detailed methods information, is usually stored with the data.
The power of rich metadata
Well described metadata records show the power of rich metadata in making research data collections discoverable, citable, reusable and accessible for the long term.
Two-Rocks moorings data 2004 - 2005 metadata record in the CSIRO Data Access Portal contains 35 metadata fields which enable researchers to quickly and accurately assess the relevance of this dataset to their research. The metadata record and the data are closely linked through co-location on the same access page. The Files tab contains additional metadata about each of the 17 files within this collection: file type, last modified, and file size.
Rich metadata allows records to be syndicated to other data catalogues; here is the same Two-Rocks mooring data record syndicated to:
- Research Data Australia: Australia’s aggregated research data catalogue
- Marlin Oceans and Atmosphere: a discipline-specific metadata catalogue