Statistical quality assurance

We have published a Statistical Quality Assurance Strategy. We plan to update this at key stages of the census journey.

The strategy provides an overview of how we will assess and measure the quality of how we:

• collect and process census data
• produce and release census outputs

Assurance of processes

We are developing robust methodology and processes for each step of the census data journey. This is a key part of ensuring quality in our work. These steps are:

• capture and coding 
• data cleansing
• administrative data
• edit and imputation
• Census Coverage Survey
• estimation and adjustment
• statistical disclosure control
• outputs

Before we start using these methodologies, they undergo peer and external review. Our strategy has also been reviewed in this way.

Read more about our assurance of processes methodology.

Internal and external assurance

In May 2023 Registrar General Dr Janet Egdell wrote to Alistair McAlpine (Chief Statistician for Scotland) setting out the assurance steps that NRS was taking ahead of publication of first outputs from Scotland’s 2022 Census.

This included assessment by Office for Statistical Regulation (OSR) to publish as National Statistics, a statement from the International Steering Group on the statistical methods used and a review of the work that NSR will undertake on the coherence of census outputs with other statistics and data.

Janet asked Alistair in his capacity as Chief Statistician for Scotland to lead the review on coherence prior to publication. Her letter and Alistair’s response are published below.

• Letter from Registrar General to Chief Statistician
• Response from Chief Statistician 

National Statistics Accreditation

Additionally, the Office for Statistics Regulation is assessing our work against the Code of Practice for Statistics.

Read more about Office for Statistics Regulation assessment.

Validation of population estimates and topic-based analysis

Other quality assurance activity includes:

• validation of population estimates, through comparing our national and local authority estimates to other data
• topic-based analysis, through comparing our topic-based population estimates with other data

Read more about our validation of population estimates methodology.

Read more about the quality of the comparator data sources used in quality assuring the census estimates.

Read more about our planned quality assurance panels engaging local authorities and topic experts

Quality assurance in UK censuses

We work closely with the other UK censuses to harmonise our efforts around quality assurance.

To support this, we have jointly set up the UK Statistical Quality Working Group. Through this group, we meet regularly with the Office for National Statistics and the Northern Ireland Statistics and Research Agency. The group meets 4 times a year to discuss:

• methodology
• best practice
• lessons learned
• opportunities for joint working

Quality assurance in international censuses 

We work with other censuses around the world to share experiences and lessons learned. Learning from other censuses can help us make improvements to our own quality assurance. Countries we work with include:

• Canada
• Republic of Ireland
• USA
• Australia
• New Zealand 

Stakeholder engagement

We would like feedback from stakeholders and census users on our quality assurance plans. Send your feedback to: [email protected]

In November 2019, we presented our quality assurance strategy to the Population and Migration Statistics Committee (Scotland).