DOI: 10.5255/ukda-sn-7209-1
title: Census 2001: Controlled Access Microdata Sample Test File (CAMS)
title: 2001 UK Census
title: Census Microdata

description: &lt;p&gt;&lt;span style="color: rgb(50, 49, 50); font-family: &quot;Open Sans&quot;, Helvetica, Arial, sans-serif; font-size: 14px;"&gt;The UK censuses took place on &lt;/span&gt;29th April 2001&lt;span style="color: rgb(50, 49, 50); font-family: &quot;Open Sans&quot;, Helvetica, Arial, sans-serif; font-size: 14px;"&gt;. They were run by the Northern Ireland Statistics &amp; Research Agency (NISRA),  General Register Office for Scotland (GROS), and the Office for National Statistics (ONS) for both England and Wales. The UK comprises the countries of England, Wales, Scotland and Northern Ireland.&lt;/span&gt;&lt;br&gt;&lt;/p&gt;&lt;p&gt;&lt;span style="color: rgb(50, 49, 50); font-family: &quot;Open Sans&quot;, Helvetica, Arial, sans-serif; font-size: 14px;"&gt;Statistics from the UK censuses help paint a picture of the nation and how we live. They provide a detailed snapshot of the population and its characteristics, and underpin funding allocation to provide public services.&lt;/span&gt;&lt;/p&gt; The &lt;i&gt;Controlled Access Microdata Sample Test File&lt;/i&gt; (CAMS) test file is a sub-sample of 298,912 cases from the Individual CAMS from the 2001 Census. Variables have been perturbed to ensure that no sample members can be identified. Perturbation has retained the correct distribution of each variable but the relationships between variables will not give expected results. The test file can therefore be used to develop and test statistical software syntax for analyses before going to use the CAMS at the Office for National Statistics (ONS). It cannot be used to test exploratory analyses with any reliability, nor will it provide the ability to test statistical procedures which are dependent on distributions. It is not suitable for research purposes and has been provided only as a dummy dataset for preparing syntax in advance of using the CAMS file. The protection comes from perturbing multiple variables per person with a high probability of change and by providing no indication of whether a variable value has been perturbed. The CAMS test file only covers individuals in private households in England and Wales, and excludes students living away from their parental home and households of six people or more. These limitations do not apply to the full CAMS files. Other differences may apply in terms of variable availability. &lt;br&gt;
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Further information about the Test CAMS may be found on the Cathie Marsh Centre for Survey Research &lt;a href="http://www.ccsr.ac.uk/sars/" title="Samples of Anonymised Records"&gt;Samples of Anonymised Records&lt;/a&gt; website. Users should consult the codebook for the full CAMS file prior to applying to use the data or preparing syntax. &lt;br&gt;
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The application procedure for the full CAMS data is available on the ONS &lt;a href="http://www.ons.gov.uk/ons/about-ons/who-we-are/services/unpublished-data/census-data/individual-cams/index.html" title="Census 2001 Individual CAMS"&gt;Census 2001 Individual CAMS&lt;/a&gt; and the &lt;a href="http://www.ons.gov.uk/ons/about-ons/who-we-are/services/unpublished-data/census-data/household-cams/index.html" title="Census 2001 Household CAMS"&gt;Census 2001 Household CAMS&lt;/a&gt; webpages.&lt;br&gt;
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