Data collection methods and instruments

Computer Aided Personal Interviewing (CAPI)

In common with many other large-scale government surveys, the SHS social interview is carried out using Computer Aided Personal Interviewing (CAPI). This offers a number of important advantages over traditional pen-and-paper interviewing for a survey of this kind.

CAPI programming is integral to ensuring high quality data. The main parameters of the data are defined within the programme, such as; the acceptable range of responses to a question; the acceptable relationships between questions – or, the routing; and the relationships between responses given at different questions.

Social survey questionnaire structure

The social questionnaire is in two parts:

• household – Information is collected about the composition and characteristics of the household from the Highest Income Householder or their spouse/partner. This allows the SHS to produce information representative of Scottish households. A ‘random school child’ is also selected, and the household respondent answers questions about the school that child attends and how the child travels there.
• random adult – Information is collected focusing on the attitudes and experiences of a randomly selected adult member of the household. This element also covers the ‘Travel Diary’ component which asks about travel behaviours on the day previous to that of the interview day. This produces data representative of the Scottish adult population resident in private households.

The questionnaire has been designed to give flexibility in terms of topic, frequency and geography. For example, questions asked of the full sample and asked on an annual basis would be able to provide local authority level estimates on an annual basis. Similarly, questions might be asked of 1/3 of the sample on a biennial basis (i.e. asked every second year). Such questions would provide national level estimates.

The 2023 questionnaire is provided as a supporting document to this publication.

Physical survey

At the end of the household component of the survey, the household respondent is asked if they would be willing to have the follow-up component ‘physical survey’ of the dwelling arranged. These are conducted by professional surveyors through a visual inspection of the dwelling, to assess the condition, design and energy efficiency of the home. Physical survey appointments are generally made for between 7 and 14 days after the interview date.

Survey fieldwork

The social survey fieldwork for the 2023 sample began in February 2023 and completed in early February 2024. The physical survey fieldwork began in February 2023 and completed in late February 2024. 

Before the first interviewer visit, households were sent an advance letter and leaflet outlining the purpose of the survey and the importance of participation. Interviewers were given the advance letters to post themselves in order that the letter would arrive a day or two before their first call. This helped to ensure that householders were likely to be aware of the letter and leaflet when the interviewer first visited. While face-to-face interviews were the aim and presented as the preferred option to householders, householders were also given the option of a remote (telephone or video) interview if required.

The main fieldwork for the survey has an on-going monthly cycle. Interviewers were required to make up to six calls at an address (an initial visit plus five ‘call-backs’). In addition to the immediate reissue of contact sheets that had been wrongly completed or where the required number of call-backs had not been made, there was an on‑going programme of reissuing ‘non-contacts’ in a bid to maximise the response rate.

On occasion, when an interviewer arrived at a sampled address, they would find that an address comprised more than one dwelling or household. In these cases, interviewers were required to select a household/dwelling at random using a Kish grid.