Background
This bespoke data collection exercise was conducted to gather detailed information from sentencers in magistrates’ courts in England and Wales about how they sentence offences of possession of a bladed article or offensive weapon. The data collection was undertaken pre and post guideline to support the evaluation of the Bladed articles and offensive weapons definitive guidelines. The pre guideline data collection ran between 1 November 2017 and 30 March 2018 and the post guideline data collection ran between 23 April 2019 and 30 September 2019 and these were mainly administered online via a survey hosted on the Council’s website.
The surveys collected information regarding the date filled out and court location of the sentencing decision, some demographic details of the offenders, the relevant culpability and harm factors taken into account when each adult offender was sentenced, the subsequent sentence starting point and the outcome imposed after any reduction for guilty plea. The potential disclosure issues surrounding these data have been carefully considered and the subsequent actions that were taken to ensure that the offenders’ confidentiality has been protected are outlined in this document.
Assessment of risk
In accordance with the Government Statistical Service (GSS) guidance, an assessment of the risk of disclosure was undertaken in order to determine which features of the data may help to protect individuals’ identities and which aspects of the data may lead to disclosure risks. This is to help prevent identification of individuals and/or prevent additional knowledge of any previously unknown characteristics for those offenders sentenced for these knife and offensive weapon possession offences during the time periods of the data collection.
The following information was used to assess the level of risk:
- the sample size of the survey
- the response rate of the survey
- the likelihood that the data could be linked or matched to other data sources
- the nature and level of detail of the information collected
Applying disclosure control
The following changes were made to the data to reduce the chance of the identification of individuals and thus maintain disclosure control. This included aggregation or banding of variables, where appropriate, in order to reduce unique counts and/or the removal of any variables that could make it easier to identify an individual:
- removal of court location
- removal of date form was completed (potential proxy for sentencing date)
- cleaning and coding of free text ‘other weapon’ into a derived variable
- removal of other free text fields where the raw data were deemed too disclosive and were not deemed high enough quality to clean and recode
- aggregation of low volume counts within certain variables into bands where appropriate and not limiting further data use
- removal of any factors with counts fewer than 10
Comments on these data
- The data collection covered all magistrates’ courts in England and Wales, but the response rates were estimated at only 16 per cent for the pre guideline data and 34 per cent for the post guideline data. This means that a substantial proportion of offenders sentenced for a possession offence during the period of the pre or post guideline data collections did not have a form filled in for them and are not captured in the data. Therefore, if someone knew some details about an offender sentenced for these offences during the period of the data collection and found a unique record in the data that seemed to match that individual, they still could not be certain that the record in the data relates to that specific person. As such, the Council considers that the data are sufficiently anonymous and feels that a higher level of disclosure control would be detrimental to the usefulness of the data.
- The likelihood has been judged as very low that individuals can be identified in the published data through linking to another dataset, given the lack of other publicly available data sources of the same information, and that the sample cannot be replicated.
- The names of the courts and date that the survey was filled out in the pre and post guideline periods have been removed and, as such, it is not possible to identify exactly where the sentencing took place or when any particular form was filled in.
- Where the counts of records were extremely low (fewer than 10), these variables have been removed from the dataset to reduce the risk of positive identification (see the metadata file for further information).
- The age of the offender and the length of any custodial sentence were both collected in a banded format, which does limit the usefulness of the data but reduces the risk of disclosure.
- In the raw post-guideline data, sentencers were asked to provide further details of the weapon involved within a free text box, which often included very specific details. To mitigate the risk of any offender being identifiable within the data, this variable has been converted into a derived variable to allow users to still identify records involving a bladed article or knife, but in such a way that reduces the disclosure risk.
- Sentencers were asked about the ‘single most important factor’ affecting their sentence which was a free text field. This included very specific details about the offender, offence, location and other details that may have risked being disclosive, so this variable has not been published.
- It is also acknowledged that the cases about which these data relate would have been heard in open court. Although this may increase the risk of identification due to some of the defendant’s details being more accessible, the impact is anticipated to be negligible due to the factors listed above. However, it also means that the impact of any potential disclosure issues is minimal as much of this information is already in the public domain.
If users would like any further details of the disclosure controls applied to the data, please contact the Analysis and Research team at research@sentencingcouncil.gov.uk.