Our approach

1.1 For this third and final stage of our Assessment, we split our work into two strands:

• A review of NISRA’s Census 2021 outputs against the Code of Practice for Statistics, with particular consideration of the extent to which the outputs have met user needs.
• A review of NISRA’s progress towards any outstanding commitments it made in response to the census Phase 2 requirements (as outlined in Annex 1).

1.2 This report was prepared by an Assessment team composed of OSR statistics regulators. The team conducted desk research and engaged with key stakeholders and users to gather its findings. The report was then approved by the Regulation Committee on behalf of the Board of the UK Statistics Authority, on the advice of the Director General for Regulation.

Desk research

1.3 While the census results were confirmed as National Statistics (now called accredited official statistics) in 2022, our desk research determined that the outputs continue to comply with the standards of Trustworthiness, Quality and Value in the Code of Practice for Statistics. This research involved reviewing the outputs over the course of 2024 to confirm their accessibility, means of dissemination and methodological information, as well as many of the supporting resources, reference materials and assurance mechanisms published by NISRA alongside the outputs.

1.4 These findings were complemented by information that NISRA shared with the OSR Assessment team, which focussed on the progress it had made against each of the census Phase 2 requirements. We also conducted two interviews with senior members of the NISRA census team to discuss our findings and seek further insight. We thank NISRA and its staff for their cooperation during this process.

User engagement

1.5 In developing this report, we spoke to users of the Census 2021 outputs in Northern Ireland. OSR conducted 11 interviews with a wide range of users of the Census 2021 outputs from Northern Ireland government departments, local authorities, charities and academia. These included those with a statistical background, researchers, policy developers and non-expert interested stakeholders. We also interviewed NISRA’s counterpart in the Republic of Ireland, the Central Statistics Office (CSO). The interview period ran from 1 October to 3 December 2024.

1.6 The information collected in this interview process complemented that gathered in an online survey that OSR ran in the summer of 2024 for Census 2021 output users, which received nine responses relevant to Northern Ireland. The online survey was advertised on OSR’s website and also sent by email to known users of NISRA’s statistics. It was run alongside a survey seeking feedback from users on the 2021 England and Wales Census outputs.