This classification relates to the 2001 Census and is specified for 2001 Output Areas. This classification has been superseded by later editions based on more recent Census data (2011, 2021) and geography, but remains available for reference and historical comparison.
The 2001 Classification for Output Areas (2001 OAC) is a hierarchical geodemographic classification across the UK which identifies areas of the country with similar characteristics. The 2001 OAC was developed collaboratively by the Office for National Statistics and the University of Leeds. The classification contains the following breakdown of Output Areas into different supergroups, groups and sub-groups.
Content
The data is available for download from the bottom of this page. Also available are pen portraits and a lookup table which provides additional description about this project.
Quality, Representation and Bias
A journal article accompanies 2001 OAC which provides a thorough evaluation. All data used for this classification are sourced from the 2001 Census so bounded by the usual operational quality / representation and bias of a national census. The geodemographic classification created presents a best effort of the authors to represent the characteristics of the population and geographic context, however, there are decisions made during the classification process that guide these representations. For a full overview of these decisions and their rationale, see the published paper.
