UK DATA ARCHIVE: IMPORTANT STUDY INFORMATION

Study Number 5854 - Quarterly Labour Force Survey, January - March, 2001


DATA PROCESSING NOTES


Data Archive Processing Standards

The data were processed to the UK Data Archive's A* standard. This is the Archive's highest standard, and means that an extremely rigorous and comprehensive series of checks was carried out to ensure the quality of the data and documentation.�Firstly, checks were made that the number of cases and variables matched the depositor's records. Secondly, checks were made that all variables had comprehensible variable labels and all nominal (categorical) variables had comprehensible value labels. Where possible, either with reference to the documentation and/or in communication with the depositor, labels were accordingly edited or created. Thirdly, logical checks were performed to ensure that nominal (categorical) variables had values within the range defined (either by value labels or in the depositor's documentation). Lastly, any data or documentation that breached confidentiality rules were altered or suppressed to preserve anonymity.

All notable and/or outstanding problems discovered are detailed under the 'Data and documentation problems' heading below.

Data and documentation problems

Income weight:
Users should note that the income weight variable PIWT07 is not currently available for this quarter; the file includes only the person weight variable PWT07.

Ethnicity variables
Users should note that none of the variables related to ethnic group are currently present in the Jan-Mar 2001 dataset, including Ethcen15. The depositor notes that there were problems with the Ethcen15 variable, including all cases missing for March. At the time of the reweighting exercise, the ethnicity variables were not updated due to these issues, and have not been included in the reweighted dataset. Continuity resumes from the Apr-Jun 2001 quarter (SN 5418), where full data are available.

Variables omitted due to SOC changes (occupation, wage and social class):
In March 2001, the occupation classification used in the LFS changed from SOC 90 to SOC 2000. Only the cases from March have been coded to the detailed SOC 2000 classification, apart from the self-employed. As a result of the change from seasonal to calendar quarters for the LFS, it was not possible for ONS to provide consistent occupation data for the Jan-Mar 2001 quarter. The occupation data is an essential part of the earnings weighting, as it is used in both the edit and the calibration totals. It was not possible to use the SOC 2000 associated variables to weight just the March data and the SOC 90 variables for January and February as there were not sufficient cases in one month to weight separately. Therefore, the Jan-Mar databases could only be produced with person-level weighting and will not include occupation or earnings-based variables. Variables affected/omitted include Hourpay, Grsswk, Grsswk2, and occupational variables such as Sc2klmj, Sc2klmn, Sc2kmmj, Sc2kmmn, Sc2ksmj, Sc2ksmn and Soc2km. Social class variables were also affected/omitted due to the change in SOC codes where earnings or occupation variables would have been used to identify social class. Continuity resumes in the Apr-Jun 2001 quarter (SN 5418).

Useful Notes

This study was deposited in 2008, as a result of the move from seasonal to calendar quarters for the QLFS, and the reweighting process to 2007-2008 population figures (see documentation for further details of reweighting).

It combines data from previously-available QLFS seasonal quarter datasets. The depositor has advised that small revisions to the data may have been made during this process, but they should not be significant.

Data conversion information

From January 2003 onwards, almost all data conversions have been performed using software developed by the UKDA. This enables standardisation of the conversion methods and ensures optimal data quality. In addition to its own data processing/conversion code, this software uses the SPSS and Stat/Transfer command processors to perform certain format translations. Although data conversion is automated, all data files are also subject to visual inspection by a UKDA data processing officer.

With some format conversions data, and more especially internal metadata (i.e. variable labels, value labels, missing value definitions, data type information), will inevitably be lost or truncated owing to the differential limits of the proprietary formats.�A UKDA Data Dictionary file (in rich text format), corresponding to each data file, is usually provided for viewing and searching the internal metadata as it existed in the originating format. These files are called: [data file name]_UKDA_Data_Dictionary.rtf

Important information about the data format supplied

The links below provide important information about the format in which you have been supplied the data. Some of this information is specific to the ingest format of the data, that is the format in which the UKDA was supplied the data in. The ingest format for this study was SPSS

Please click below to find out information about the format that you have been supplied the data in.

SPSS (*.por)

STATA (*.dta)
Tab-delimited text (*.tab)
MS Excel (*.xls files)
SAS (supplied as *.dat and *.sas)
MS Access (*.mdb files)

Conversion of documentation formats

Electronic and paper documentation supplied with this study is usually incorporated into the UKDA User Guide (in PDF format). The conversion programmes used are the latest versions of Adobe PDF Writer for electronic documentation and Adobe Paper Capture (Acrobat 'plugin' version) for paper documentation. Occasionally, some�of the electronic documentation cannot be usefully converted to PDF (e.g. MS Excel files with wide worksheets) and this is supplied in�a more appropriate format. All User Guides are fully bookmarked.