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Census 2021 comparability documents

Date published: 15 December 2022

Statistics: Census 2021,  Census 2021 results,  Census 2021 reference materials

Explore how the census questionnaire evolved over a decade.

Overview

This report details key differences between the 2011 and 2021 Census questionnaires in Northern Ireland, helping users understand where changes in definitions or response options - not population shifts - may explain differences in results.

The report highlights:

  • Changes in question wording, structure, and content
  • Impacts on data comparability
  • Rationale for additions, removals, or updates

An outputs comparability document will follow shortly. It will identify the equivalent census table produced in 2011, indicating any differences, and whether the output is comparable.

Documents

  • 2021-2011 Census in Northern Ireland questionnaire comparability report Adobe PDF (396 KB)

Help viewing documents

Last updated: 29 May 2025

Links

  • Official Statistics producer – Upholding Trust, Quality and Value
  • General Register Office - registration and certification of life events relating to births, deaths and marriages
  • nidirect.gov.uk – the official government website for Northern Ireland citizens
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