Frequently asked questions about the census
What is the census?
The national census counts all people and households in the UK. It asks questions about employment, living arrangements, transport, health, ethnicity and migration. It gives a complete snapshot of the nation.
A national census has taken place every 10 years since 1801, except in 1941. The 2001 census was taken on 29 April 2001.
The 2001 census was based on where people live rather than where they were on census night. Students and children were counted at their term-time address. Where households were absent, eg away on holiday, they were obliged to complete a census form on their return.
Why is the census taken?
The census provides a rich resource of information on the number of people, where they live and what their needs are. It is widely used by government and local authorities to plan the provision of public services, such as schools, libraries, housing and transport.
The information is used to identify differences between areas or groups of people and trends over time.
How is the census data collected?
It is a legal requirement within the UK to complete a census form. In 2001, every household and institution (such as a hostel or hall of residence) was provided with a census form to complete on census day. Attempts were also made to count those sleeping rough, on boats and so on. Self-completion forms were to be filled out by the head of the household.
For the first time, the census in 2001 was based wholly on residents – where people usually live rather than where they were on census night. Students and schoolchildren living away from home were counted at their term-time address.
Forms were processed electronically and the collated information was checked for data quality. Copies of each form were transferred to microfilm and will not be made available as public records until after 100 years.
What types of questions are asked in the census?
The census asks questions on a wide variety of topics, including population, housing, employment, health, ethnic group and transport. Visit the Census background for a full list.
In 2001, several new items were included for the first time:
- lowest floor level of accommodation
- religion
- general health
- provision of unpaid personal care
- length of time since last employment
- supervisor status
- size of workforce of employing organisation
- ethnic sub-categories for mixed groups and Irish
- a new social classification (National Statistics Socio-Economic Classification or NS-SeC )
- a category for ‘separated but still legally married’ under marital status.
What measures are taken to ensure that the numbers are correct?
The One Number Census project evaluates whether the census represents the entire population. It aims to integrate the census counts with an estimate of the proportion of people the census misses. This included an independent follow-up survey.
The Census Coverage Survey (CCS) involved face-to-face interviews with a sample of 320,000 households from every local authority in the UK. In the past, the total population given by the census was the raw count, reflecting a response rate of 98%. In 2001, by combining the results of the census with the CCS, it was possible to estimate the total resident population, effectively creating a 100% sample.
At what geographical level can I get census data?
The smallest building block for 2001 census data is the output area (OA), which is an area of approximately 125 households created from an amalgamation of post codes. In East Sussex there are around 1740 OAs, which can be added together to create custom-built areas, such as housing estates.
Census data is available at the following geographical levels:
National
- England
- Wales
- Scotland
- Northern Ireland
Regional
- Government Office Regions, eg South East
- strategic health authorities
Local
- counties, eg East Sussex
- parliamentary constituencies
- county electoral divisions
- primary care trusts
- local authorities: districts, boroughs and unitary authorities, eg Eastbourne Borough Council, Rother District Council
- parishes, eg Ditchling, Crowhurst
- wards, eg Plumpton, Battle, Frant
- output areas
What table formats will be used?
Census results are available in various formats.
The following sets of tables are available for all levels of geography, from output areas upwards:
- key statistics – summarising the main census results in about 24 simple tables;
- univariate tables – presenting many of the simplest census counts in about 64 tables;
- census area statistics tables – presenting more complex cross-tabulations of census results in 80 tables; and
- census area theme tables – grouping results in seven tables (for East Sussex) for different sections of the population, such as dependent children and older people.
The following, more detailed sets of tables are only available for higher levels of geography, such as district wards and above:
- standard tables – presenting the most detailed information, cross-tabulating results in 112 tables for East Sussex; and
- standard theme tables – grouping results in 17 tables for sections of the population (such as dependent children and older people) and for particular topics (such as ethnic group and religion).
What data will be available for very small parishes?
Some administrative areas contain so few people that the confidentiality of the results for people living there may be at risk. To preserve confidentiality for these areas, such as the smallest parishes, only very limited data will be available.
In 1991, the cut-off point ( or ‘threshold’) detailed census results were only made available for areas with at least 50 persons and 20 households. Four civil parishes in East Sussex were smaller than this threshold (Tarring Neville, Penhurst, St John (Without) and Southease) and the data for each of these areas was combined with a neighbouring parish.
For the 2001 census data will be restricted for areas with less than 100 persons and 40 households. However, the Office for National Statistics has agreed to provide summary profiles (simple counts and percentages) for any areas that fall below the new threshold but above the 1991 limit.
Restrictions on the availability of data can be summarised as follows:
- Areas with at least 100 persons and 40 households: no restrictions on available data; data not combined with adjoining parish
- Areas with fewer than 100 persons and 40 households but with at least 50 persons and 20 households: data restricted to summary profiles (a subset of the key statistics); data will be combined with adjoining parish
- Areas with fewer than 50 persons and 20 households: data restricted to summary counts only of total males, total females, total persons and total households; data will be combined with adjoining parish.
Data will be restricted if just one of the minimum number requirements is not met – for example, for an area with 100 persons and 39 households only profiles will be made available.
In the 2001 census the parishes that fell below the size threshold will also have their results combined with larger adjacent parishes and more detailed results will be made available for these combined areas.
Following consultation with the affected areas, the Office for National Statistics has decided to combine the 2001 census results for the following parishes:
-
Lewes District
- St. Ann (Without) to be combined with Falmer
- Southease to be combined with Rodmell
- Tarring Neville to be combined with Beddingham
- St. John (Without) to be combined with East Chiltington.
-
Rother District
- Penhurst to be combined with Ashburnham
- East Guldeford to be combined with Playden.
I am interested in other areas in the UK. Where is this data available?
Information for other parts of the UK can be found at:
When will further information become available?
The Office for National Statistics will publish further specialised datasets and geographies later in 2003, after the publication of small-area data in August 2003.
I want to quote census figures in my report, am I able to do this?
Check with your organisation or with the Stationery Office to see whether you need a click-use licence. These are free from the Stationery Office and allow the reproduction of census data from the Office for National Statistics.
Can individuals be identified in the census and are results confidential?
No person or household can be positively identified from the census data. The Office for National Statistics has strict guidelines to maintain confidentiality. For the 2001 Census, this involved both record swapping (where whole records are ‘moved’ from one administrative area to another) and small cell adjustment (where small numbers within particular tables may be increased or decreased slightly).
Can I compare results from previous censuses with the 2001 Census?
Figures from previous censuses can be compared with the 2001 Census but an exact comparison may not always be possible because of changing definitions over time. For example:
- in 2001, students have been counted differently (at their term-time address rather than at their home address) – thus the numbers of young people shown as living in university towns and in communal establishments (halls of residence) are affected
- the 2001 data has been adjusted to correct the count, using a technique from the One Number Census project whereas previous censuses were not adjusted to compensate for ‘missing’ persons
- all data for 2001 was collected on a resident basis only and there is no information available on persons present on census night as in earlier censuses in 1991, communal establishments (such as children’s homes and prisons) were counted differently as ‘special enumeration districts’ (SEDs). In East Sussex there were 61 SEDs in 1991 but there are none in the 2001 Census.
Are there any special datasets available?
Specially analysed or prepared results from the 2001 Census are available:
- Flow data
This records flows of people, including journeys to work and migration. This needs specialised software for analysis, and grouping of data tailored to the specific area of interest.
- Samples of Anonymised Records (SARs)
These were developed for the 1991 Census to provide a small sample of the whole census so that people could analyse original results in their own ways. This means you can explore the characteristics of your chosen subset of the population, such as the labour market characteristics of women with children of pre-school age.
For the 1991 Census there were two datasets – a 2% sample of the population and a 1% sample of households. East Sussex County Council did not make use of 1991 SARs data because the samples were not suitable (Hove was grouped with Lewes for example). It is hoped that the 2001 data will be constructed differently so that local authorities as well as academics will be able to make use of it.
I don’t understand some of the terms used in the census information, where can I find definitions for these?
Download from this link a list of definitions in pdf format published by the Office for National Statistics.
Who should I contact if I need more information?
You can get further information about the data for East Sussex from
For detailed information about the census process and for other areas of the UK, please contact:
For England and Wales:
Census Customer Services
Office for National Statistics
Titchfield
Fareham PO15 5RR
Tel: 01329 813800
Fax: 01329 813587
email: census.customerservices@ons.gov.uk
Web: www.statistics.gov.uk/census2001
For Scotland:
Census Division
General Register Office for Scotland
Ladywell House
Ladywell Road
Edinburgh EH12 7TF
Tel: 0131 314 4254
email: customer@gro-scotland.gov.uk
Web: www.gro-scotland.gov.uk
For Northern Ireland:
Census Customer Services
Northern Ireland Statistics and Research Agency
McAuley House
2-14 Castle Street
Belfast BT1 1SA
Tel: 028 9034 8160
Fax: 028 9034 8161
email: census.nisra@dfpni.gov.uk
Web: www.nisra.gov.uk
What does the information cost?
Access to the main results of the 2001 Census is free and use is unrestricted. ONS have initiated a project called Census Access with the aim of delivering main results in an unrestricted, user-friendly and largely electronic way.
The access package is available free to all users and includes:
- all standard local tables
- extended tables with more detail
- complete geographical framework
- output for changed areas after 2001
- re-use and publication through free click-use licence.
Customised output will also be available from ONS for a small charge.
