Metadata Basics

What is metadata?

Metadata is essentially information about data. It describes, among other things, who collected it, why it was collected, the methods used to collect it and how it can be used. Metadata provides all the information a data user needs to assess whether the data resource is fit for use. Metadata allows users to:

  • Know who created the data and for what purpose
  • Know when the data was created
  • Know the geographic extent or coverage of the data (for geospatial data)
  • Understand how the data was created and manipulated
  • Understand the limitations of the data with respect to use
  • Understand any legal limitations to access and use of the data
  • Determine tools needed to view, manipulate, and use the data
  • Know how to access the data

Metadata is important to both the dataset provider and other potential users. High quality metadata allows dataset owners to keep an inventory of datasets they have created, with the ability to locate the data and recall the circumstances and context under which it was created and analysed. When publicly available, metadata enables other interested parties the ability to discover, understand and use the data to its fullest potential.

What are metadata standards?

A metadata standard is a specification which establishes a common understanding of the meaning (or semantics) of data, to ensure correct and proper use and interpretation by its owners and users. Many standards begin as schemas, which group metadata elements into sets designed for a specific purpose (e.g. for geospatial data) to enable the best possible description of a data resource in that context. For every element the name and semantics are specified, along with any rules on how content must be formulated and represented, and where element values are to be identified from controlled lists.

The development of such schemas tends to be controlled through community consensus combined with a formal processes for submission, approval and publishing of new elements. Schemas that are developed and maintained by standards organisations (e.g. ISO) or organisations that have taken on such responsibility (e.g. Dublin Core Metadata Initiative) are called metadata standards.

The UK Geospatial Metadata Interoperability Initiative (GEMINI ) is the UK’s geographic metadata standard. It was originally produced through a collaboration between the Association for Geographic Information (AGI), the e-Government Unit (eGU) and the UK Data Archive. An application profile of ISO 19115, UK GEMINI is conformant with the INSPIRE Technical Guidance and designed to meet the requirements of INSPIRE in a UK context.

Why create metadata?

Metadata adds significant value to any organisation’s data holdings, and failure to create it can lead to hidden costs generated at a later date. Undocumented data soon loses its value as staff change and institutional knowledge is lost. Subsequent staff with little understanding of the contents and use of the data and may lose confidence in results generated by it.

Beyond the individual organisation, data resources are a major national asset. Information of what data resources exist within different organisations, particularly within the public sector, is required to improve efficiencies and reduce data duplication. Metadata standards enable interoperability between organisations and platforms. Metadata from a variety of sources can be integrated into other technical systems or machine read by compatible ones. Adoption of metadata standards greatly increases the potential for data discoverability.

Data can only be useful if it can be interpreted and understood, and can only be used if it can be found. Creating and maintaining standard compliant metadata secures the financial investment that organisations put into data by:

  • Retaining institutional knowledge
  • Enabling better decision making through the use of appropriate data
  • Avoiding costly duplication of effort through lack of knowledge about data
  • Minimising the risk of unintentional use through good documentation
  • Increasing the value of data by unlocking its potential for re-use
  • Supporting collaboration through discoverability and simplified access
  • Inspiring trust in the data source

When effort and resource is put into the provision of standard compliant metadata, organisations will be better placed to find, assess and make use of the data that is available to them – particularly in times of national emergency - saving time, money and lives.

Why use UK Gemini?

UK GEMINI is the designated standard for geographic metadata in the United Kingdom. It ensures consistency with respect to metadata across the UK through content guidance and the use of UK specific terms and code lists. UK Gemini also simplifies the INSPIRE Technical Guidance making it easier for organisations to achieve compliance.

While ensured compliance to regulations is important, the key benefit is the interoperability the standard allows across a range of platforms. Metadata in the Gemini format can be shared and consumed easily by a number of platforms and third party applications. Gemini is a requirement for the data.gov.uk portal and, with version 2.3, can now be consumed by the ESRI ArcGIS platform without the need of additional plugins.