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Guide to classifications

Statistics are usually compiled from a large set of individual observations.

In order to make conclusions, these observations need to be grouped or 'classified'.

A classification assigns items to categories according to shared characteristics and it provides a framework for the description and comparison of statistics.

Classifications facilitate the accurate and systematic arrangement of data according to common properties so that the resulting statistics can be easily reproduced and compared over time as well as between different sources.

Classification is thus an essential part of statistics, and standard classifications are key instruments of official statistics.

One of the key principles of the National Statistics Code of Practice and Protocol on Statistical Integration is the promotion and use of common statistical frames, definitions and classifications.

In the United Kingdom, three widely-used standard classifications are the: 
  • Standard Industrial Classification (SIC)
  • Standard Occupational Classification (SOC)
  • National Statistics Socio-economic Classification (NS-SEC)
Regular reviews of standard classifications are conducted to ensure that economic and social changes are reflected in the classification and, where relevant and possible, that the classification is comparable with European and international standards.

Many other classifications are used throughout National Statistics.

Some have been developed by individual or groups of Government Departments while others have been taken directly from European or international use.

Advice 

The Industrial Classifications Branch maintains and promotes the Standard Industrial Classification. The unit runs a help desk to provide advice and guidance to customers. For more information, please contact classifications.helpdesk@ons.gov.uk

The Occupational Information Unit maintains and promotes the Standard Occupational Classification and the National Statistics Socio-economic Classification. The unit runs a help desk to provide advice and guidance to customers. For more information, please contact occupation.information@ons.gov.uk

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