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Scottish Household Survey - Survey Details

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Survey Details

This section provides background information on the Scottish Household Survey.
 

Overview | Methodology | Survey Content | Data Limitations | Managing Survey Development | Survey Review | List of Topics | Variable Lookup

Methodology

Overview

The structure of the survey is a continuous cross-sectional survey, each complete sample being covered in the course of two years. As well as keeping down the annual cost of the survey and making the volume of fieldwork more manageable, a continuous survey will, in time, enable national trends to be detected sooner than would periodical surveys.

The sample is being drawn from the small user file of the Postcode Address File (PAF). The overall design of the sample is to pursue a wholly random sample where fieldwork conditions allow - namely in areas of high population - and to cluster interviews in the remaining areas (also on a random basis).

To allow sufficient disaggregation of the survey results, an achieved sample of approximately 31,000 households over two years is required. The sample in each quarter is geographically representative so that statistically reliable results for Scotland as a whole are available for each quarter. In addition, the survey design is such that results are available for each of the larger local authorities (those with an achieved sample size of 750 interviews per year) each year, and for all local authorities, regardless of size, every two years.

The Highest Income Householder, or his/her partner/spouse, is interviewed face-to-face about themselves and other members of the household. In addition, a randomly selected adult member of the same household aged 16 or over (who may, by chance, be the same person) is interviewed on other topics. In this way, results from the survey are representative of both Scottish households and adult individuals.

Computer Assisted Personal Interviewing (CAPI) is being used to collect the survey data. This has a number of important advantages over 'pen and paper' interviewing techniques, including faster interviews, automatic edit checks and a quicker flow of information from the survey interviewer to the survey database.

Further details about the survey methodology can be found in latest technical report found on the Publications page.

Weighting

Current Weighting Strategy

The Scottish Household Survey (SHS) previously used a fairly simplistic weighting strategy. It was intentionally simple, and reflected, in part, a desire to keep the processes of the survey straightforward so that data could be made available for analysis as quickly as possible. It also reflected the limited extent to which SHS data differs substantially from comparator data. Thus, no additional corrective weighting had ever been applied to the data beyond that required to account for sample design and differential response rates between local authorities.

This aspect of the survey has been subject to review, as part of a study comparing non-respondents to the SHS with Census data. Whilst comparison with the Census showed some bias in the SHS, this was not substantial, although some corrective weighting was recommended.


Weighting Strategy Review

During 2008 and 2009, the SHS contractors were asked to make proposals for developing and implementing a revised weighting strategy for the survey. The key driver behind this is to account for any non-response bias in the estimates, and for the strategy include the production of grossing factors to allow the survey to provide numerical, population based, estimates for survey measures (rather than the current percentages).

A report has been produced which outlines the outcomes of the review in assessing the SHS weighting strategy and an evaluation of impact on key estimates.

  • Scottish Household Survey - Weighting Strategy Review 2009

Further information on the weighting strategy used is available through our range of publications, in particular the Methodology and Fieldwork Outcomes report:

Income Imputation

Income Imputation

During autumn 2008 the Scottish Government commissioned a feasibility study into the possibility of using data from the Family Resources Survey to improve the quality of income estimates produced from the Scottish Household Survey (SHS) and Scottish House Condition Survey (SHCS). The work also included examining the way in which income data in the SHS and SHCS were recorded and processed.

For further information on this study please see the following site:


We are currently working with Income and Poverty colleagues to evaluate the proposed recommendations and consider ways in which these can be implemented within the SHS.


Further information on the current income imputation strategy used within the SHS are presented in a number of our publications:

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