Requirement 1: NRS should publish information and assurance for users so they can understand the expected quality of census data. This should be communicated in an accessible and timely way ahead of outputs. NRS should be open about how its users’ needs will be met or how it plans to address any unmet needs.

Evidence provided by NRS on actions taken since 2023 in response to the requirements

NRS published information on enhancements to the methodology for producing census outputs in June 2023, ahead of the first 2022 census outputs in September 2023.

NRS published a quality assurance report at the same time as each main census publication. Therefore, it was not possible to provide this information ahead of the accompanying outputs.

OSR’s evaluation of evidence

Requirement met. Information on methodology published ahead of outputs in June 2023, including the use of key performance indicators on accuracy, helped users understand the anticipated quality before outputs were first released. Quality assurance reports provided alongside outputs were comprehensive. Users were generally confident in NRS’s communication of how well the outputs would meet their needs. Time constraints required Statistical Quality Assurance to be done in parallel to outputs. While NRS was unable to meet the precise timeliness of the requirement to provide quality information ahead of outputs, key quality information was provided to users alongside outputs. We did not hear any concerns from users regarding this approach; it therefore did not undermine the overall assessment that the requirement has been met.

Requirement 2: NRS should be transparent about its approach to public engagement with regard to its confidence in data quality. NRS should review its communication and engagement plans, prioritising users where concerns over data quality are greatest and where there is most risk from inaccurate census estimates.

Evidence provided by NRS on actions taken since 2023 in response to the requirements

NRS involved local authorities in a series of quality assurance (QA) panels prior to the first 2022 census outputs. More information on these panels was published in the QA report accompanying first outputs.

NRS published information on plans to form QA panels in August 2022. These involved topic experts from NRS, ONS, Scottish Government and Transport Scotland, with one panel running for each topic release.

NRS published the statistical quality assurance strategy on the Scotland’s Census website. This document outlines why statistical quality assurance, quality control and quality management are important for the 2022 census. It sets out the approach to statistical quality assurance, and explains how the strategy will evolve.

Contact details were provided to users to contact NRS who wanted to get in touch regarding the QA process.

NRS held stakeholder webinars in June 2023 on quality prior to publishing first outputs from the Scotland’s Census which provided information about the work that has been carried out to deliver high-quality statistics. This came alongside a presentation in June 2023 which was promoted among stakeholders to provide information on the work conducted to produce high-quality census outputs.

OSR’s evaluation of evidence

Requirement met. Overall, NRS has made clear efforts to be transparent in its public engagement on data quality, particularly with key stakeholders and specialist users, and has actively communicated its methodologies and confidence in the census outputs. The statistical quality assurance strategy clearly outlined how quality would be assessed, and this materialised through generally effective communication of quality across the outputs. The variety of methods NRS used to engage with a range of users were effective.

NRS’s engagement has a strong emphasis on specialist or institutional users, but the evidence suggests less targeted outreach to general public audiences or groups beyond formal committees that may also have concerns about data quality. NRS may want to consider this as part of planning for Census 2031.

Requirement 3: NRS should ensure that, when it publishes statistics on trans history or produces demographic breakdowns by sex, these are accompanied by clear information on the definitions and guidance used to produce those statistics. NRS should explain the coherence and comparability of its statistics from the 2022 census with those from other censuses, especially given the differences in guidance for the census sex question.

Evidence provided by NRS on actions taken since 2023 in response to the requirements

NRS took several measures in addressing Requirement 3 regarding the publication of statistics on trans history or producing demographic breakdowns by sex. The measures taken by NRS included:
• A clear definition of trans status of history when publishing the main sexual orientation and trans status or history release.
• The sexual orientation and trans status or history quality assurance report included more information on trans status, including data comparing to results from the England and Wales 2021 Census, information on trans status or history by English-language proficiency and data on trans status or history by sex.
• Information was provided in the first release of census data on the sex question along with a link to the sex question guidance provided to census respondents.
• Detailed estimates for each of the 27 trans status or history coding framework categories have been published to allow users to explore this data in more detail

OSR’s evaluation of evidence

Requirement met. NRS has met Requirement 3 by publishing trans history and sex breakdown statistics with clear definitions, explanations of how the data were collected, and quality assurance documentation. Guidance on interpretation in the context of previous censuses and other UK census data through detailed topic reports was also provided. The context and history surrounding the new question and its performance were presented sensitively. OSR received no specific user feedback around the performance of this question or the information which NRS has made publicly available during this assessment process. NRS informed OSR that the data are still being used, indicating that users are satisfied with the information provided. Some feedback on this topic has been provided to NRS during the 2031 topic consultation, which we expect to be integrated into planning for the next census. We also expect NRS to continue to follow our guide for collecting and reporting data about sex and gender identity in official statistics.

Requirement 4: NRS should ensure that supporting documentation, guidance and information on data quality, including bias and uncertainty, is communicated in its outputs. This information should be refreshed and added to as its programme of outputs is delivered. For known areas of user interest, for example for data on sex, NRS should provide detailed information on quality indicators, such as the outcomes from its quality assurance processes, in assessing census estimates against other data sources.

Evidence provided by NRS on actions taken since 2023 in response to the requirements

NRS published a quality assurance report at the same time as each main census publication. This contained detailed information on quality, and any data issues which users should consider when interpreting census data.

Advice for users making comparisons between population groups was published to help users understand census data. Tips were provided to users to help them avoid making incorrect conclusions based on these comparisons.

Information comparing census results to other sources, including the mid-year population estimates and administrative-based population estimates, was published to allow users to easily compare census data with these key sources of population data. This was intended to increase confidence in the quality of the data, including for sex.

Age-standardised data, including for Census 2011, were published for the health, disability and unpaid care topic. This allowed users to more easily compare differences between groups with different age profiles.

COVID-19 impacts were communicated in the QA report for education, labour market and travel to work. The effect of COVID-19 was more pronounced for some data published in this release, for example in travel to work data. Evidence from other sources was used to illustrate this and allow users to consider this when interpreting the census results.

Detailed quality information on imputation rates for each applicable census variable was published, allowing expert users the opportunity to interrogate this key measure of data quality.

OSR’s evaluation of evidence

Requirement met. NRS has broadly met the intent of the requirement by publishing comprehensive quality information alongside census outputs, producing topic-specific quality assurance reports, including peer review panels and coherence assessments with other data sources, including uncertainty and interpretative guidance in initial and future output releases, and refreshing its statistical quality assurance strategy as outputs progressed. The impacts of the pandemic on collection and response have been communicated well, alongside advice for users on making comparisons between population groups.

Regarding data on learning disability in Scotland, quality concerns resulted in a noticeable gap for users who had been expecting clear and useable outputs. However, within the extremely broad range of topic areas and outputs, NRS’s overall commitment to providing supporting documentation, guidance and information on data quality is impressive and has been received well by users.

Requirement 5: NRS should take further steps to communicate plans and provide more-detailed information to users of UK census data in Scotland. NRS should continue to work together with the other census offices to explain any impacts on UK census data quality and describe where user needs may or may not be met as a result.

Evidence provided by NRS on actions taken since 2023 in response to the requirements

NRS worked with ONS and NISRA to assess the impact on comparability due to the difference in census dates (following NRS’s pushback due to COVID-19). Each variable was assessed to determine whether they were still broadly comparable or if comparisons were to be avoided. Wording was agreed across the three census offices, including wording to be shared with stakeholders alongside advice on combining the results. Signposting was included towards where users can find data from the respective census offices. Links to ONS and NISRA were included on each statistical report published by NRS. Information on comparability was also included in the metadata for census variables. This highlighted any differences in questions which the data was derived from.

ONS identified a user need for UK census outputs which was not met by its, NRS’s and NISRA’s existing approach to comparability. NRS and NISRA worked closely with ONS to provide UK census estimates. The outputs estimated 2021 census estimates for Scotland to produce a 2021 estimate. The methodology was agreed between the three census offices, simple linear interpolation between the 2011 and 2022 census. All three offices worked closely on the methodology, and supporting information was published alongside estimates – including details on methods, QA and strengths and limitations of the data. These were published on the ONS website. NRS also has a webpage with info on UK census data, linking to the ONS publication.

OSR’s evaluation of evidence

Requirement met. NRS has taken several important steps toward meeting Requirement 5, especially in terms of continuous collaboration with ONS and NISRA on UK census data issues, creating structures (like the UK census data working group) to help coordinate user engagement at the UK level, and working with ONS to include information about impacts on UK census data quality in its published documentation. Responsibility for leading much of this work sits with ONS, and our assessment of NRS’s activity on UK outputs aligns with our Phase 3 reports of the 2021 census in England and Wales and Northern Ireland. The UK census estimate outputs were published in June 2025 and were received positively by users. OSR received no user concerns about UK-level outputs or UK comparability while conducting this assessment.