BackgroundThe Annual Population Survey (APS) is a major survey series, which aims to provide data that can produce reliable estimates at local authority level. Key topics covered in the survey include education, employment, health and ethnicity. The APS comprises key variables from the Labour Force Survey (LFS) (held at the UK Data Archive under GN 33246), all of its associated LFS boosts and the APS boost. Thus, the APS combines results from five different sources: the LFS (waves 1 and 5); the English Local Labour Force Survey (LLFS), the Welsh Labour Force Survey (WLFS), the Scottish Labour Force Survey (SLFS) and the Annual Population Survey Boost Sample (APS(B) - however, this ceased to exist at the end of December 2005, so APS data from January 2006 onwards will contain all the above data apart from APS(B)). Users should note that the LLFS, WLFS, SLFS and APS(B) are not held separately at the UK Data Archive. For further detailed information about methodology, users should consult the Labour Force Survey User Guide, selected volumes of which have been included with the APS documentation for reference purposes (see 'Documentation' table below). The APS aims to provide enhanced annual data for England, covering a target sample of at least 510 economically active persons for each Unitary Authority (UA)/Local Authority District (LAD) and at least 450 in each Greater London Borough. In combination with local LFS boost samples such as the WLFS and SLFS, the survey provides estimates for a range of indicators down to Local Education Authority (LEA) level across the United Kingdom. Secure Access APS data Secure Access datasets for the APS include additional variables not included in the standard End User Licence (EUL) versions (see under GN 33357). Extra variables that typically can be found in the Secure Access version but not in the EUL versions relate to:geographytypes of benefits claimedqualifications, education and training, including level of highest qualification, qualifications below highest level, class of first degree, single subject of degree, qualifications from Government schemes, number of O-levels/GCSEs etc passed, type of 'other qualification', type of other work-related or vocational qualifications, qualifications related to work, sources of qualifications, qualifications from school, level of Welsh baccalaureatefrequency of Welsh speakingcasual/holiday workregular/normal work patternreasons not in work or for leaving work, reasons not looking for workpayment of own National Insurance and taxsmoking habits single year of agehealth issueslearning difficulty/disabilitynumber of bedroomsserving in armed forcesmarital statusmain reason for coming to the UK The EUL version contains less detailed variables. For example, the lowest geography is Government Office Region, only banded age is available, only 3-digit SOC is available for main, second and last job, and only industry division for main, second and last job. Prospective users of the Secure Access version of the APS will need to fulfil additional requirements, commencing with the completion of extra application forms to demonstrate to the data owners exactly why they need access to the extra, more detailed variables, in order to obtain permission to use that version. Secure Access data users must also complete face-to-face training and agree to the Secure Access User Agreement and Licence Compliance Policy (see 'Access' section below). Therefore, users are encouraged to download and inspect the EUL version of the data prior to ordering the Secure Access. Further details and links to all APS studies available from the UK Data Archive can be found via the APS Key Data series webpage. Documentation and coding frames The APS is compiled from variables present in the LFS. For variable and value labelling and coding frames that are not included either in the data or in the current APS documentation (e.g. coding frames for education, industrial and geographic variables, which are held in LFS User Guide Vol.5, Classifications), users are advised to consult the latest versions of the LFS User Guides, which are available from the ONS Labour Force Survey - User Guidance webpages. Disability variables from 2013 onwards - LFS and APS ONS have provided some information on changes since 2013 to the disability variables available on the LFS and APS. The Disability Discrimination Act (DDA) disabled (current disability) category within the historic DISCURR variable no longer corresponds with the advised legal definition of 'current disability'. DISCURR should only be available on LFS microdata from Spring 1998 to January-March 2013 (JM13); beyond that point users should ignore or delete it.