The main population base for published statistical tables from the 2011 Census in Northern Ireland is the usual resident population base as at Census day, 27 March 2011. By way of background, for 2011 Census purposes a usual resident of the United Kingdom (UK) is anyone who, on Census day, was in the UK and had stayed or intended to stay in the UK for a period of 12 months or more, or had a permanent UK address and was outside the UK and had intended to be outside the UK for less than 12 months.
Against this background, the 2011 Census Microdata Sample of Anonymised Records (SARs) Teaching File comprises a sample of 19,862 records (approximately 1 per cent) relating to people who were usually resident in Northern Ireland at the time of the 2011 Census. For each individual, information is available for seventeen separate characteristics (for example, sex, age, marital status) to varying degrees of detail. Both the size of the sample and the content of the records in the file have been harmonised, wherever possible, with the equivalent SARs teaching file that the Office for National Statistics simultaneously released for England and Wales.
The primary purpose of the teaching file, which comprises unit-record level data as opposed to statistical aggregates, is as an educational tool aimed at:
- encouraging wider use of Census data by facilitating another way of examining Census data, for example through the building of statistical models, over and above that already available through the raft of standard tabular output released to date;
- providing a broad insight into the sort of detail that is generally included in a SARs product, along with data formats and any associated metadata. This will enable users (arguably those less experienced at using SARs products) to ‘play’ with the data and increase their knowledge and skills in readiness for accessing the more detailed SARs products that are planned and will be available in, for example, a safe setting; and
- assisting with the teaching of statistics and geography at GCSE and higher levels.