Metadata

Collating and recording metadata is important for the purposes of cataloguing, citing, discovering and retrieving data collections. Metadata are a subset of core data documentation providing standardised, structured information.

Metadata are intended for reading by machines, and help to explain the purpose, origin, time references, geographic location, creator, access conditions and terms of use of a data collection. Without this essential documentation, collections become of limited value simply because researchers and reusers will not be able to search for or cite the data collection.

With new policies and initiatives asking researchers to pre-register their studies and to share their data, catalogued information about research studies has shown the importance of having metadata clearly documented from the very start of a research study.

Example schemes

• Dublin Core
• ISO 19115 for geographic information
• Data Documentation Initiative (DDI)
• Statistical Data and Metadata eXchange (SDMX)
• Metadata Encoding and Transmission Standard (METS)
• General International Standard Archival Description (ISAD(G))
• DataCite metadata schema for the publication and citation of digital datasets with a persistent identifier.

Data Documentation Initiative

The DDI is a rich and detailed metadata standard originally designed for describing social, behavioural and economic sciences data. It is used by most social science data archives in the world.

DDI catalogue records contain mandatory and optional metadata elements relating to study description, data file description and variable description. The study description contains information about the context of the data collection, such as bibliographic citation of the study and data, the scope of the study, like topics, geography, time, method of data collection, sampling and processing, data access information, and information on accompanying materials.

The data file description indicates data format, file type, file structure, missing data, weighting variables and software used. Variable descriptions indicate the variable labels and codes.

The UK Data Service uses DDI to structure catalogue records. The use of standardised records in eXtensible Mark-up Language (XML) brings key data documentation together into a single document, creating rich and structured content about the data.

Metadata can be harvested for data sharing through the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).

The UK Data Service catalogue records

Our DDI records contain mandatory and optional metadata elements on the following:

• Study description – information about the context of the data collection, such as bibliographic citation of the study and data, the scope of the study (topics, geography, time), methodology of data collection, sampling and processing, data access information, and information on accompanying materials.

• Data file description – information on data format, file type, file structure, missing data, weighting variables and software.

• Variable descriptions.

We collect the initial catalogue record information from our data deposit form, which is completed by the data depositor. We then enhance information from the accompanying documentation to create a conformant metadata record.

Where researchers can provide detailed and meaningful data collection titles, descriptions, keywords, contextual and methodological information in the deposit form, it helps us to create rich resource-discovery metadata for their deposited collections. We assign keywords from our own HASSET thesaurus.

Data citations

Depositors are encouraged to provide information about original and subsequent reports and publications or presentations based on our data collections, so these references can be added as further documentation.

We are always interested in capturing case studies of data reuse in our collections to encourage further use of data. We prepare a standard bibliographic citation for each data collection so that users can correctly cite the data sources in research outputs.

Example extract from a UK Data Service DDI catalogue record