Scottish Crime and Justice Survey 2018/19: main findings

1. Introduction and background to the SCJS

What is the SCJS and what purpose does it serve?

The Scottish Crime and Justice Survey (SCJS) is a large-scale social survey which asks people about their experiences and perceptions of crime. It is completed face-to-face in the homes of respondents, with sections on more sensitive topics completed by the respondent themselves using the interviewer's laptop or tablet as part of the main interview.

This report presents the results for the eighth SCJS, with interviews conducted between April 2018 and May 2019. The 2018/19 survey is based on around 5,500 face-to-face interviews with adults (aged 16 or over) living in private households in Scotland.

The main aims of the SCJS are to:

• enable the Scottish population to tell us about their experiences of, and attitudes to, a range of issues related to crime, policing and the justice system; including crime not reported to the police
• provide a valid and reliable measure of adults' experience of crime, including services provided to victims of crime
• examine trends over time in the number and nature of crimes in Scotland, providing a complementary measure of crime to police recorded crime statistics
• examine the varying risk and characteristics of crime for different groups of adults in the population

Findings from crime surveys in Scotland have been used by policy makers across the public sector, academia and third sector to help understand the nature of crime in Scotland, target resources and monitor the impact of initiatives since the 1980s. The results of this survey provide evidence to inform progress against the Scottish Government's National Performance Framework (NPF)^[1] and a range of other metrics used across the justice system.

What do I need to know when reading this report?

Detailed information about the history, design and methodology of the SCJS is provided in the accompanying Technical Report to help you understand the strengths and limitations of the survey's results. Annex D also provides guidance on how to interpret the charts and tables contained in this report. The sections below provide summary information on: the background to the SCJS, the reliability of survey estimates and how uncertainty around results is explained, as well as an overview of the content of this report and other SCJS supporting outputs.

Who is included and what does the SCJS cover?

The SCJS does not aim to provide an absolute estimate for all crime and has some notable exclusions.

The SCJS is a survey of adults living in private residential households (including private and social rented housing) and therefore does not provide information on crimes against adults living in other circumstances (for example tourists and those living in institutions or communal residences, such as prisons or hospitals, military bases and student accommodation). The survey also excludes people under the age of 16 and crimes against businesses. Further details on the sampling approach is outlined in the accompanying Technical Report.

The SCJS is primarily a victimisation survey which captures information on adults' experiences of violent crime and property crime, including those not reported to the police. However, it does not capture data on all crimes – for example, crimes with no direct or specific victim to interview (e.g. speeding, drug possession and homicide). Experiences of sexual offences are not included in the main estimates and are instead collected in the self-completion section and reported separately.

Throughout the report, the term 'crime' is used to refer to any in-scope incident recorded by the survey, occurring during the interview reference period and in Scotland, in which the respondent or their household as a whole was the victim.

The survey also explores perceptions of the police, the justice system and safety in Scotland.

How is the survey delivered?

The design of the 2018/19 SCJS was broadly similar to the approach used since 2008/09. Therefore, when examining changes over time, this report generally compares the latest findings to those in 2008/09 and the last SCJS in 2017/18.

Other summary points to note on the methodology are outlined below.

• Survey frequency: Since 2008/09 the frequency of the SCJS has varied a little. In 2016/17, the SCJS reverted to being conducted on an annual basis. The 2018/19 SCJS is the latest annual survey.
• Sample: The sample is designed to be representative of all private residential households across Scotland. A systematic random selection of private residential addresses was produced from the Royal Mail's Postcode Address File (PAF) and allocated in batches to interviewers. Interviewers called at each address and then selected one adult (aged 16 or over) at random from the household members for interview.
• Questionnaire: The questionnaire consists of a modular design completed by the interviewer using Computer-Assisted Personal Interviewing (CAPI) and a self-completion section covering sensitive crimes using Computer-Assisted Self Interviewing (CASI). Annex C gives an overview of the questionnaire structure and general topics, and the most recent questionnaire is available on the SCJS website.
• Fieldwork: Interviews were conducted on a rolling basis between April 2018 and May 2019, with roughly an equal number of interviews conducted across most months.
• Interviews: 5,537 face-to-face interviews were conducted in respondents' homes by professional interviewers from an original target of 6,000. The achieved response rate was 63.4%, against a target of 68%. This was similar to the achieved response rate in 2016/17 (63.2%) and 2017/18 (62.4%), but lower than the 67.7% achieved in 2012/13.
• Interview Length: An average interview lasted around 40 minutes, though there was variation in interview length, depending on the respondent's reported experience of crime.
• Time period covered: Respondents were asked about incidents experienced in the 12 months prior to the month of interview (the reference period). The time period covered by the data on experiences of crime included in this report extends over 25 months (from the start of April 2017 to the end of April 2019) so is not directly comparable with any calendar year.
• Weighting: The results obtained were weighted to correct for the unequal probability of selection for interview caused by the sample design and for differences in the level of response among groups of individuals.

Further information about the design and methodology is contained in the accompanying Technical Report.

How reliable are SCJS results?

The SCJS gathers information from a sample rather than from the whole population and, although the sample is designed carefully, survey results are always estimates, not precise figures. This means that the results are subject to a margin of error which can have an impact on how changes in the numbers should be interpreted, especially in the short-term.

To indicate the extent of uncertainty, this report presents key results on the extent and prevalence of crime using both best estimates and lower/upper estimates. The best estimate is the mean figure drawn from the sample. The lower and upper estimates are for the 95% confidence interval. Aside from these key findings, the majority of the analysis provided in the report focuses on best estimates.

Because of sampling variation, changes in reported estimates between survey years or between population sub-groups may occur by chance. We therefore use standard statistical tests to examine whether differences are likely to be due to chance. Only differences that are statistically significant at the 95% confidence level are described as differences or changes within this report.

Where no statistically significant change has been found between two estimates, this has been described as showing 'no change' (or equivalent). The presentation of uncertainty and change in this report reflect best practice guidance produced by the Government Statistical Service (GSS)^[2].

Uncertainty can be particularly high around some crime incidence estimates, often where experiences are less common and incident numbers are derived from the experiences of a relatively small number of victims in the sample. We assessed the uncertainty for crime incidence figures in this report by computing the relative standard error (RSE) around the results and have flagged results which have RSE values greater than 20%^[3]. We recommend that such results are used with caution.

What findings are included in this report and where can I access additional results?

The report is split into sections which focus on presenting data for the majority of topics covered by the survey questionnaire including: the extent, prevalence and nature of crime in Scotland; perceptions of the police and justice system; and consideration of how evidence from the SCJS compares to and complements police recorded crime statistics in Scotland. The report does not include in-depth, multivariate statistical analysis that would explore the more complex underlying relationships within the data.

This report contains a range of demonstration tables and charts within the body of each chapter. Further information on how to interpret charts, tables and data presented in this report is provided in Annex D. Many of these tables and charts include breakdowns by respondent characteristics such as age, gender, deprivation, urban/rural and victim status. Further detail on many of these tables, for example with additional breakdowns, and full time series results, are provided in the data tables presented in Annex A.

We have also released a more comprehensive set of SCJS data tables alongside this report which present further breakdowns of results, from a wide range of survey questions, by geographic, demographic, attitudinal or experiential characteristics of respondents.

The raw survey data files and survey documentation will be available soon after publication of this report from the UK Data Service.

Data collected by the self-completion element of the SCJS (on drug use, stalking and harassment, partner abuse and sexual victimisation) is collated over two survey years and published biennially. Key findings on each of the self-completion topics from SCJS interviews conducted in 2016/17 and 2017/18 can be found in the 2017/18 Main Findings Report. Supporting data tables have also been published to provide additional findings from these questionnaire sections. Key findings on each of the self-completion topics will next be available in the 2019/20 Main Findings Report.

SCJS results provided to Police Division level are available biennially (as they have been since 2012/13), with two survey years' worth of data combined to increase the sample size and precision around results with effect from 2016/17. Key results at Police Division level covering the period 2016/17 – 2017/18 are available alongside the 2017/18 Main Findings Report^[4]. Findings released include perceptions of the police, as well as wider SCJS results such as victimisation rates, within each Division. They are most easily accessed in the SCJS interactive data tool which has been developed to enable divisional results to be compared over time, as well as against each other and the national average for each survey year^[5]. Police Division level results for 2018/19 and 2019/20 combined will be provided alongside the 2019/20 Main Findings Report. Further information on the SCJS reporting structure is available on the SCJS website.

How can I find out more about the SCJS?

Scottish Crime and Justice Survey - User Engagement

The SCJS is used in multiple ways and by a range of users across government, public services, academia and third sector. Engaging effectively with users is important in ensuring that the SCJS meets their needs.

If you want to find out more about the Scottish Crime and Justice Survey or any other work undertaken by the Scottish Government Statistics Group, you can access information through the following ways:

SCJS User Group

The SCJS team have established a user group to ensure that user engagement is an on-going part of each survey cycle. Members are drawn from government, academia, the justice system and third sector. The user group is an essential way to ensure that the survey remains relevant and able to respond to changing needs - for example, in helping to determine and design questionnaire content. If you would like to become involved in the user group, please contact us.

ScotStat

Register with ScotStat: a network for users and providers of Scottish Official statistics. It aims to improve communication amongst those interested in particular statistics and facilitate the setting up of working groups on specific statistical issues. For example, we provide updates about up-coming publications and on-going questionnaire development work via ScotStat.