Metadata is often called ‘data about data’. More precisely, it is the underlying definition or structured description of the content, quality, condition or other characteristics of data.
It is well accepted in the world of statistics and large databases that metadata leads to better data. This is because they enable all people collecting, using and exchanging data to share the same understanding of its meaning and representation.
Metadata that have been endorsed for use across Australia are referred to as data standards.
Data can be defined as a representation of facts, concepts or instructions while metadata can be defined as a structured description of the content, quality, condition or other characteristics of data. Metadata needs to accompany data, otherwise the data being transmitted or communicated cannot be understood. For example, the value 185 can be transmitted in a data file. However it is meaningless without additional information. Is it a street number, a clinical measurement, a test result or the number of services provided?
Adding information about the unit of measure (e.g. centimetres) makes a data value more meaningful, but still cannot be fully understood. Adding information about what the data relates to (e.g. a person) and what it is measuring (e.g. their height) makes for more useful data. Additional details of how the measurement was made (e.g. self-reported) could be added to further improve the utility of the data.
Therefore when a data value (e.g. 185) is transmitted or linked to a specific metadata item (e.g. Person—body height (self-reported), total centimetres NNN), the meaning is also made clear and can be understood by the recipient.
Types of metadata in METeOR
Metadata items are items that proceed through a series of registration states until they become endorsed as standards by the relevant registration authority. This means that metadata items become official data standards. There are eight metadata items currently used in METeOR:
- Object classes
- Data element concepts
- Data elements
- Value domains
- Classification schemes
- Data set specifications
- Glossary items
Navigational items are items that are added to METeOR by the Registrars to make the navigation and management of metadata items easier and more meaningful. This means that navigational items are not official data standards. There are two navigational items currently used in METeOR: