Key elements of the 2021 Census

This section highlights the key elements of the 2021 Census which includes how we are planning on ensuring inclusion and supporting respondents, engaging with our stakeholders and plans for publicising the census.

Questionnaire completion

As a ‘digital-first’ census, householders will be encouraged to complete online.  Around 90% of all householders will receive a letter enclosing a unique access code (UAC).  The 2021 Census online questionnaire will be designed to allow for completion on most common web browsers and mobile devices. Functionality will be designed to minimise burden and improve data quality.

Where necessary, a paper questionnaire will be provided to the public. The paper questionnaire will be designed to be easy to fill out. All paper questionnaires will be provided to respondents with a pre-addressed, pre-paid return envelope. The paper questionnaire will have space for up to six persons in each household and will be provided to the public in the following circumstances:

  • for around 10% of householders a paper questionnaire will be part of the initial contact (for example, in areas where online access is difficult)
  • when requested by members of the public, via the public support channels
  • when handed out to householders on the doorstep by field staff
  • finally, towards the end of the census period, all non-responding households will be sent a paper questionnaire to ensure they have a full opportunity to fulfil their statutory duty

Alongside this, anyone may ask for a separate (individual) online or paper questionnaire. This will help in households where individuals desire privacy. In larger households (of more than six residents) householders will be able to complete their return online but, if completing on paper, will need to request a continuation paper questionnaire for the seventh and further residents.

Developing a census address register

The accuracy of the 2021 Census depends on counting every household and communal establishment in Northern Ireland.  We will develop a census address register from a range of data sources that contain address information.  Field staff will undertake a full on-the-ground address check to confirm that the census address register is complete and accurate.  The census address register will also be checked by field staff in advance of the rehearsal in October 2019 for the rehearsal areas.

Alongside this, a full list of communal establishments will be developed in liaison with public bodies and other organisations.

Follow up of non-responding households

The census operation will be designed to encourage the majority of questionnaires to be completed online.  For those who have trouble completing the questionnaire online, there will be a number of support options including providing paper questionnaires on request.   While we expect the majority of households to complete their questionnaire on or before Census Day, other householders will need encouragement and support after that date.

As with previous censuses, we will use different strategies to contact non-responding households and encourage them to take part.  For some, this will take the form of a targeted reminder letter.  For others, field staff will initially call door-to-door. Ultimately every household which has not responded will receive one or more visits from field staff.

The role of field staff will include making contact with non-responding households, encouraging participation, highlighting the benefits of the census to households and individuals and providing assistance for completion as required.  As time progresses, the emphasis will shift to the legal requirement for completing the census and the penalty for not doing so.

Communal establishments

As well as private households the census needs to capture the characteristics of people living in around 1,200 communal establishments (for example, hotels, hospitals, boarding schools or prisons).  We will establish a dedicated team, based in Census Office, to manage this. This team will work with managers of communal establishments to ensure that a response is made.

Providing support to the public

We will offer a wide variety of services to provide all respondents with the help and assistance they require.  Assistance will be available online, via a contact centre with a dedicated telephone number, via social media and through field staff calling door-to-door.  We will also develop a community liaison plan for the 2021 Census to improve awareness and coverage amongst communities which are traditionally ‘hard to reach’.

We will provide the census questionnaire and explanatory material in Braille and large print. Guidance booklets and a translation of the questionnaire will also be available in a number of additional languages (up to sixteen languages other than English).  NISRA propose that the online questionnaire will also be available in Irish and Ulster-Scots, similar to Scotland where it is planned to offer Scots Gaelic.

Publicising the census

Every census presents a unique publicity challenge in that it means communicating with, and motivating, every household to fill in their census questionnaire.   We will run a large scale communications campaign, including TV, radio, outdoor and digital advertising, to explain the purpose and value of the census. The campaign will aim to:

  • ensure all householders know that the census is happening
  • encourage all householders to complete their questionnaire, ensuring that they are aware of their legal obligation to make a return
  • provide assurances to the public about the confidentiality and security of the census
  • inform the public about how they can get more information

The goal of the publicity campaign is to allay any concerns and motivate householders to take part, whilst also giving the public access to information on all options for support.

Use of administrative data

A significant change from 2011 will be a greater use of administrative data in the design and conduct of the 2021 Census.  Administrative data is information that people have already provided to government, for example, in the course of accessing public services.

There are three areas where administrative data will improve the efficiency, effectiveness and quality of the 2021 Census, these are:

  • design and prioritisation
  • operational improvements
  • statistical quality and outputs

Any use of administrative data in the census would be subject to legal, ethical and privacy considerations.  More information on the use of administrative data can be found at 2021 Census: Use of administrative data.

Data Processing

Census returns will be processed to obtain a fully complete database of the whole population of Northern Ireland.  It is anticipated that most respondents will complete their census questionnaire online, although those respondents preferring to complete a paper questionnaire will be able to do so.  Completed paper questionnaires will be scanned and the data captured, coded and amalgamated with the online questionnaires into a single dataset. As with the 2001 and 2011 Censuses, the capture and coding of data from paper questionnaires will be outsourced.

For the 2021 Census, it is planned that NISRA will conduct all subsequent data processing of Northern Ireland census returns.  Before publishing any results, detailed final statistical quality assurance processes will be undertaken including disclosure control. Such processes will examine, at both the macro and micro level, the results to ensure that the final statistics are accurate, non-disclosive, coherent and that no systematic error has been created.

Quality Assurance

The publication of 2021 Census results is the culmination of a series of processes, from developing the census questions, collecting and processing the data, to the production and dissemination of statistical outputs. Each of these processes could introduce some degree of error and therefore, in ensuring quality of the results, it is important to consider quality assurance at every stage of the census process. The 2021 Census Quality Assurance Strategy outlines the quality assurance work that will be undertaken by NISRA to ensure that the outputs released from the 2021 Census are robust, reliable and meet the needs of users.

Our approach to quality assuring each of these processes is to:

  • understand each process and the nature of any error or uncertainty that might be introduced
  • estimate the expected size and impact of potential errors within key processes in order to prioritise our checks effectively
  • where possible, define metrics that allow us to understand the size and nature of these errors during the 2021 Census

Census outputs

For 2021, we aim to maintain or, if possible, improve on the quality of outputs produced from the 2011 Census. The proposed design, content and dissemination of 2021 Census outputs can be found in the 2021 Census: Outputs Strategy for Northern Ireland consultation document.

The key elements of the outputs strategy are:

  • the results will be published as soon as possible after data processing; with initial results published by summer 2022 and all remaining pre-planned outputs by summer 2023
  • outputs will be produced using recognised international classifications which will aid understanding
  • we will use the internet as the primary dissemination facility
  • comprehensive metadata, in the form of definitions, classifications and quality indicators, will be supplied
  • we will develop a more flexible dissemination system, moving away from the traditional high volume of pre-specified tables

Keeping your census data safe

There is a well-established reputation of maintaining confidentiality in the census and it is intended to uphold this reputation in the 2021 Census.

Census data are held under a set of official standards and safeguards which have been put in place to ensure that the data remains secure. This includes control of physical access to any site or room where the data are kept and secure control of access to IT hardware and IT systems.

The information collected in the census will be used solely for the production of statistics and for statistical research. Personal census information will not be made available or used for other purposes. There are legal penalties for unlawful disclosure of census personal information.

In releasing aggregate statistics from the 2021 Census, precautions will be taken to ensure that published tabulations and abstracts of statistical data do not reveal any information about identifiable individuals or households. Special precautions may apply particularly to statistical outputs for small geographic areas or small population groups.

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