A:1. Introduction
A:The large data set (LDS) is a pre-released set or sets of data that should be used as teaching material throughout the course.
A:The purpose of the LDS is that learners experience working with real data in the classroom and explore this data using appropriate technology. It is principally intended to enrich the teaching and learning of statistics, through which learners will become familiar with the context and main features of the data.
A:See the specifications for OCR's A Level in Mathematics (H240) and AS Level in Mathematics (H230) for more information.
A:The Large Data Set (LDS) consists of four sets of data: two each from the censuses of 2001 and 2011; two on method of travel to work and two showing the age structure of the population.
A:All four show data by Local Authority District (LAD), or Unitary Authority (UA), for England and Wales. Each LAD/UA is also labelled with its region and its nine character geography code introduced from January 2011. The first three characters of the code provide information about the level of geography:
A:E06: Unitary authority in England
A:E07: Non-metropolitan district in England
A:E08: Metropolitan borough in England
A:E09: London borough.
A:W06: Unitary authority in Wales
A:The term "Local Authority" will be used in examination questions to refer to one of these when its type is not known, and to a group of more than one of these types, e.g. "All of the Local Authorities in the North East region."
A:Some Local Authorities were merged for census purposes between 2001 and 2011; these changes have been reflected in the LDS so that each sheet uses the same 348 output areas. For more details on the merge, see section 7. Unitary Authorities.
A:Links are provided below to the data tables from which these data were extracted. These web pages also include notes on the sampling and metadata.

A:2. Method of Travel 2011
A:The data are from Census Table CT0015EW. The information in table CT0015EW is produced using both a person's place of work and their method of travel to work. This alters the key statistics table from 2011 (QS701EW) to match the 2001 specification for comparison.
A:http://webarchive.nationalarchives.gov.uk/20160105160709/http://www.ons.gov.uk/ons/rel/census/2011-census-analysis/method-of-travel-to-work-in-england-and-wales/art-method-of-travel-to-work.html
A:Method of travel to work
A:The method of travel used for the longest part, by distance, of the usual journey to work. This topic is only applicable to people who were in employment in the week before the census.
A:The “All Categories of people in employment” column is the sum of all people in work to aid comparison with 2001. The column of data on people not in employment has been retained from CT0015EW as a separate entry for interest.

A:3. Method of Travel 2001
A:The 2001 data are from Census Table KS15 available within the 2001 census key statistics tables on the Neighbourhood Statistics Website
A:http://www.neighbourhood.statistics.gov.uk/dissemination/Download1.do
A:The local authorities have been updated to match the 2011 Area codes see “7. Unitary Authorities”.
A:The “All Categories of people in employment” column is the sum of all people in work; the data are unchanged from KS15.

A:4. Age Structure 2011
A:The data are from Census Table KS102EW available within the 2011 census key statistics table on the nomis website.
A:https://www.nomisweb.co.uk/census/2011/key_statistics
A:Age is derived from the date of birth question and is a person's age at their last birthday, at 27 March 2011. Dates of birth that imply an age over 115 are treated as invalid and the person's age is imputed. Infants less than one year old are classified as 0 years of age.
A:The columns of data on mean and median age have been retained from KS102EW as a separate entry for interest.

A:5. Age Structure 2001
A:The data are from Census Table KS02 available within the 2001 census key statistics tables on the Neighbourhood Statistics Website.
A:http://www.neighbourhood.statistics.gov.uk/dissemination/Download1.do
A:Age is derived from the date of birth question and is a person's age at their last birthday. Dates of birth that imply an age over 110 are treated as invalid and the person's age is imputed.
A:The local authorities have been updated to match the 2011 Area codes: see “7. Unitary Authorities”.
A:The entries for mean and median age have not been retained from KS02. The discussion of which of these two can be reconstructed from KS02 following the amalgamation of some local authorities into unitary authorities, and which cannot, is left as an exercise for the classroom.

A:6. Geographic information
A:Information about the geographic methods and principles used to produce 2011 Census results can be found at  
A:http://ons.gov.uk/ons/guide-method/geography/products/census/index.html

A:7. Unitary Authorities
A:The unitary authorities below were created by amalgamating former districts. In each of the two data sets from 2001, the data from these districts were summed to give the data for the unitary authority.
A:County Durham UA, operative 1 April 2009, is the same area covered by the former districts of Chester-le-Street, Derwentside, Durham, Easington, Sedgefield, Teesdale and Wear Valley.
A:Northumberland UA, operative 1 April 2009, is the same area covered by the former districts of Alnwick, Berwick-upon-Tweed, Blyth Valley, Castle Morpeth, Tynedale and Wansbeck.
A:Cheshire East UA, operative 1 April 2009, is the same area covered by the former districts of Congleton, Crewe and Nantwich and Macclesfield.
A:Cheshire West and Chester UA, operative 1 April 2009, is the same area covered by the former districts of Chester, Ellesmere Port & Neston and Vale Royal.
A:Shropshire UA, operative 1 April 2009, is the same area covered by the former districts of Bridgnorth, North Shropshire, Oswestry, Shrewsbury and Atcham and South Shropshire.
A:Bedford UA, operative 1 April 2009, is the same area covered by the former district of Bedford.
A:Central Bedfordshire UA, operative 1 April 2009, is the same area covered by the former districts of Mid Bedfordshire and South Bedfordshire.
A:Cornwall UA, operative 1 April 2009, is the same area covered by the former districts of Caradon, Carrick, Kerrier, North Cornwall, Penwith and Restormel.
A:The Isles of Scilly were recoded on 1 April 2009.  They are separately administered by an Isles of Scilly council and do not form part of Cornwall UA but, for the purposes of the presentation of statistical data, they may be combined with Cornwall UA.
A:Wiltshire UA, operative 1 April 2009, is the same area covered by the former districts of Kennet, North Wiltshire, Salisbury and West Wiltshire.


A:Copyright: table CT0015EW: Method of Travel to Work, Census 2011, © Crown copyright, Office for National Statistics licensed under the Open Government Licence v.3.0. www.ons.gov.uk
A:Copyright: Table KS15: Neighbourhood Statistics - Method to Travel, Census 2001. © Crown copyright, Office for National Statistics licensed under the Open Government Licence v.3.0. www.neighbourhood.statistics.gov.uk
A:Copyright: Table KS102EW: Age Structure Census 2011. © Crown copyright, Office for National Statistics licensed under the Open Government Licence v.3.0. www.nomisweb.co.uk