Dear David

Confirmation of National Statistics designation for 2021 Census in Northern Ireland

Tomorrow will see the publication of the first release of headline population and household statistics for Northern Ireland. The amount of work to get to this point by you and your team has been impressive and I look forward to seeing these important census estimates being released.

Thank you for your letter of 11 May 2022 which outlined how the Northern Ireland Statistics and Research Agency (NISRA) has responded to the requirements from Assessment Report 362: 2021 Census in Northern Ireland. You and your team have showed your commitment to ensure the Census 2021 statistics for Northern Ireland will be of high quality and meet the wide and varied needs of users of these data. You have made concerted efforts – throughout census development, operational delivery and in the subsequent statistical data quality assurance and processing stages – to deliver such important statistics and uphold the standards of the Code of Practice for Statistics.

On behalf of the Board of the UK Statistics Authority, I am pleased to confirm the designation of National Statistics for outputs from the Census 2021 in Northern Ireland produced by NISRA. The statistics will provide government, local authorities, businesses, researchers, and all interested parties with a rich source of information on the people in Northern Ireland in 2021. We have included the detail around our judgement in the annex to this letter.

We were particularly impressed with how you adapted and enhanced census processes,  making improvements to planned activities. For example, the Registrar General introduced a new expert quality assurance (QA) panel to advise on and assess the quality of census data. Across the range of NISRA’s data processing and QA activities, you have demonstrated evidence of the robust methods and protocols you have in place. You have also been transparent in publishing your Census QA strategy, explaining how you assure the quality of Northern Ireland census estimates for users. We were also pleased to see how your plans for the release of census data have been informed through engagement and consultation with census data users; you have put users at the centre of your planning in a way that will help to secure the greatest value from these census data. I commend you for all your work to achieve this.

Tomorrow marks the start of publication over the next year, and beyond, of a wide range of more-detailed census statistics, as set out in your release schedule. We are confident that you will continue to build on the excellent work you have done to date, to continue to provide accessible and insightful statistics, accompanied by appropriate supporting information for users. We look forward to seeing this come to fruition and my team will continue to engage with you and advise on Code compliance as required.

I am copying this letter to Siobhan Carey, Chief Executive and Registrar General for Northern Ireland, and to Sandy Fitzpatrick, Head of Census.

Yours sincerely

Ed Humpherson

Director General for Regulation

Annex: Summary of actions taken in response to Assessment Report 362: Assessment of 2021 Census in Northern Ireland run by the Northern Ireland Statistics and Research Agency  

Requirement one:

In order to support society’s need for information, NISRA needs to clearly communicate how 2021 Census data may be impacted by COVID-19 and how it plans to address any unmet user needs. NISRA should ensure this information is communicated in an accessible and timely way, being open on plans, developments and progress even where definitive answers or solutions are still being sought.

Actions taken and commitments made by NISRA to meet the requirement 

  • NISRA successfully adapted data collection operations for census live running during the COVID-19 pandemic to ensure the safety of field staff and the public. It also put in place adapted communication and enumeration strategies such as working with universities to contact and encourage student participation in Northern Ireland’s census and changed questionnaire routing so both term-time and home address data for students were captured.
  • NISRA has held meetings with the Office for National Statistics (ONS) to align any additional data processing required due to COVID-19 impacts on census data. NISRA has adapted messaging to ensure any differences on its data processing or impacts identified for Northern Ireland are appropriately reflected.
  • NISRA has provided public commitments to provide information on how data may be affected by COVID-19 alongside census outputs, for example in its Outputs prospectus published on 31 January 2022.
  • NISRA will complete its data processing and quality assurance (QA) so as to be fully informed on any impacts due to COVID-19 on census data. NISRA intends to publish supporting quality information alongside its outputs, with more detailed information to be developed and published as its outputs release phases progress.
  • NISRA plans to produce further narrative on the utility of census data – given the pandemic, Brexit, migration, Ukrainian population crisis etc – after census results are published.

OSR’s evaluation of evidence   

NISRA has successfully delivered census operations for Northern Ireland during the COVID-19 pandemic, overcoming many challenges to its systems and service delivery. The census team has worked flexibly to effectively reprioritise resources and modify its plans for the census collection period, ensuring live operations were undertaken safely for both the public and NISRA staff.

We recognise NISRA has committed publicly to provide supporting information for users on the effect of COVID-19 on census data and has made clear to us its efforts to fully investigate any issues on data quality.

We are confident that NISRA will meet its commitments to deliver this information on release of outputs, with more detailed information being made available as appropriate.

Requirement two:

To assure Northern Ireland users of how their data needs will be addressed, NISRA needs to provide users with transparent, accessible and timely information on how UK population estimates for 2021, UK Census data and Ireland-Northern Ireland data will be provided. NISRA should continue to work with, and align communications with, ONS, NRS and CSO to explain any impacts on data quality and describe where user needs may or may not be met as a result.

Actions taken and commitments made by NISRA to meet the requirement 

  • NISRA’s population estimates work plan was published on 12 January 2022, which details the various population estimates and projections outputs for 2022-23. Publication of population mid-year estimates has been moved to after the summer to keep distance from the census.
  • The Outputs prospectus includes high-level plans for UK population estimates, UK census data and NISRA has reaffirmed its commitment to producing a report and data from census 2021/22 for the island of Ireland.
  • NISRA is an active participant in a variety of cross-census office groups including the UK Census Committee. The census team has told us of its continued productive and positive relationship with ONS, NRS and Central Statistics Office (CSO) of Ireland to progress collaborative working on these matters.
  • NISRA plans to continue to update its UK census data webpage as plans for the delivery of UK census data are finalised.

OSR’s evaluation of evidence   

NISRA maintains its strong networks across Census offices and has continued to make information available to users on its broader plans for population data on Northern Ireland and for the island of Ireland.  


Requirement three:

NISRA should ensure finalised documentation on quality, information and judgements on suitable data sources, and methods and their application are complete. All supporting information should be sufficiently open and easily available to Census data users alongside its range of Census outputs.

Actions taken and commitments made by NISRA to meet the requirement 

  • NISRA told us that the use of administrative data has benefited Northern Ireland’s census from address frame to live operations – although there are limitations in availability of some data.
  • NISRA has established a new expert QA panel, reporting directly to the Registrar General, ahead of summer and autumn 2022 census releases. This panel is tasked with reviewing the methods and approach to QA, adding an additional level of assurance to its previously planned approach.
  • NISRA published its Census Quality Assurance Strategy which sets out for users how it assures the quality of Northern Ireland census estimates.
  • NISRA published data on the operational delivery of census with its outputs prospectus in January 2022. This report provided information to users and interested parties on how census operations was conducted, the measures taken to promote participation and the data collection methods used.
  • NISRA plans to publish finalised documentation including quality assurance reports and methodology reports, to support its census outputs.

OSR’s evaluation of evidence

We are assured that NISRA is following robust methods and protocols as part of its data processing and QA arrangements. NISRA has been open with issues found through QA and how it has resolved these through established QA frameworks.   

NISRA’s introduction of a new QA panel is an example of its continued commitment to adapt and enhance QA processes.  

We are confident in NISRA’s plans to provide finalised documentation on quality and methods to users alongside Census outputs.  


Requirement four:

In order to ensure the relevance of data and statistics to users, NISRA needs to continue to develop and enhance its user engagement activities, connecting with a broad range of users and embracing challenge. NISRA should continually review and seek to implement improvements in its engagement strategies and should ensure its decision making is open and transparent, being clear where users’ needs can or cannot be met.  

Actions taken and commitments made by NISRA to meet the requirement 

  • NISRA has completed its census outputs consultation which ran during October and November 2021. NISRA considers this to have been a successful exercise receiving around 50 responses. NISRA published the consultation responses on 24 March 2022.
  • NISRA has secured additional funding for social media advertising leading up to and during the release of Census 2021 outputs to raise public awareness, which will supplement its use of existing channels for communication with users.
  • NISRA has made more use of media and social media opportunities with regard census outputs during the end of 2021 and early 2022, for example to promote the publication of its outputs prospectus.
  • NISRA explained some of the new and innovative engagement routes put in place for live operations such as new social media channels on Facebook and Twitter. NISRA told us it plans to use these new routes for engagement strategies on census outputs alongside its more established routes such as its Demographic Statistics Advisory Group.

OSR’s evaluation of evidence

Through its user consultation and its promotion of the outputs prospectus, NISRA has shown good practice when it comes to keeping users and key stakeholders engaged and encouraging them to share their views to shape NISRA’s plans.

It is encouraging that NISRA continues to develop its plans for communication and promotion of census outputs, from the end of May 2022.


Requirement five:

NISRA needs to deliver its aims in relation to timely, accessible and flexible Census outputs – while ensuring sufficient data quality and supporting appropriate use of the data. It should clearly communicate its plans and timelines for outputs at the earliest opportunity, updating and revising these as soon as more detail is available or to reflect any changes to its plans.  

Actions taken and commitments made by NISRA to meet the requirement 

  • NISRA published its outputs prospectus in January 2022, giving users a broad schedule of outputs for 2022/23. NISRA will update this with further release dates when they are finalised.
  • NISRA has announced the date for the release of first census outputs for Northern Ireland – confirming these will be made available on 24 May 2022.
  • The census team continues to work closely with the NISRA branch leading on the development of the new outputs dissemination platform, which will be used for the first time for census data.
  • Work is ongoing with ONS on the development of a flexible table builder which will be similar to the ONS’ planned product.

OSR’s evaluation of evidence

NISRA has provided users with information on its plans for outputs and has worked collaboratively with partners in providing new dissemination tools for Census.  


Requirement six:

To best support Census data users, NISRA needs to continue to improve its webpage navigation for current materials. NISRA’s plans for a separate website or webpages for Census outputs themselves will require sufficient consideration of its navigation and accessibility. NISRA should keep webpages and content refreshed and current.  

Actions taken and commitments made by NISRA to meet the requirement 

  • To coincide with the publication of the outputs prospectus, NISRA completed an initial refresh of its webpages and updates these to ensure relevant and most recent information is easily accessible for users.
  • NISRA has started a review of its existing Census 2021 webpages to aid accessibility for users. NISRA will continue to update and refresh its census webpages as outputs are delivered.
  • The census team will work with NISRA’s IT support team to ensure that dissemination systems are successfully integrated with the NISRA website.

OSR’s evaluation of evidence

NISRA has continued to make improvements to its website for its users, with plans in place to further enhance web accessibility for Census outputs.  

Related links

David Marshall to Ed Humpherson: Northern Ireland Census assessment