Statistical Notice: Quality Strategy, Principles and Processes

serving the community through the administration of justice
Document Details
Date last updated: Revised June 2013
Document Authors: Statistics & Research

Statistical Notice – Quality strategy, principles and processes


Statistical quality in the Northern Ireland Courts and Tribunals Service is defined as meeting users’ needs with particular reference to the relevance, accuracy, timeliness, accessibility, comparability and coherence of the statistics collected, analysed and reported.

Four principles underpin the delivery of statistical quality in the Northern Ireland Courts and Tribunals Service:

  1. Users are identified and dealt with in a spirit of consultation and responsiveness, and their needs prioritised and met within available resources.
  2. Suppliers are respected and dealt with ethically, legally and effectively.
  3. Methodologies, processes and practices are documented to the correct level of detail for their purpose, kept up to date and made available where appropriate.
  4. Statistical processes and outputs are monitored and measured against standards with a view to their maintenance and improvement.

The definition and key components of statistical quality in the Northern Ireland Courts and Tribunals Service are contained in Table 1 below.

Table 1: Dimensions of quality in statistics

Definition Key components
The degree to which the statistical product meets user needs for both coverage and content.
Any assessment of relevance needs to consider:
  • who are the users of the statistics;
  • what are their needs; and
  • how well does the output meet these needs?
For survey data: the closeness between an estimated result and the (unknown) true value.
For administrative databases: how well the information is recorded and transmitted.
Accuracy can be split into sampling error and non-sampling error, where non-sampling error includes:
  • coverage error;
  • non-response error;
  • measurement error;
  • processing error; and
  • model assumption error.
  • completeness;
  • timeliness of recording and transmission;
  • accuracy of recording of data items;
  • correct use of coding; and
  • correct interpretation.
Timeliness and Punctuality
Timeliness refers to the lapse of time between publication and the period to which the data refer.  Punctuality refers to the time lag between the actual and planned dates of publication.
An assessment of timeliness and punctuality should consider the following:
  • production time;
  • frequency of release; and
  • punctuality of release.
Accessibility and Clarity
Accessibility is the ease with which users are able to access the data.  It also relates to the format in which the data are available and the availability of supporting information.
Clarity refers to the quality and sufficiency of the metadata, illustrations and accompanying advice.
Specific areas where accessibility and clarity may be addressed include:
  • needs of expert and non expert users;
  • consistency of standard in relation to revisions, rounding, data suppression and spreadsheet type;
  • assistance to locate information;
  • clarity; and
  • dissemination.
The degree to which data can be compared over time and domain.
Comparability should be addressed in terms of comparability over:
  • time;
  • spatial domains eg sub-national, national, international; and
  • domain or sub-population eg crime/offence type, ethnicity.
The degree to which data derived from different sources or methods but which refer to the same phenomenon are similar.
Coherence should be addressed in terms of:
  • data produced at different frequencies;
  • other statistics in the same domain;
  • sources and outputs;
  • coverage of different databases; and definitions and coding used for different databases.

Procedures to deliver quality

To put these principles and their key components into practice, reference should be made to the Northern Ireland Courts and Tribunals Service’s procedural documents identified in Table 2 below which overlap and reinforce particular aspects of delivering statistical quality in the Northern Ireland Courts and Tribunals Service.

Table 2: Delivering quality statistics in the Northern Ireland Courts and Tribunals Service

Definition Users of the Northern Ireland Courts and Tribunals Service should expect that:
  • They will be appropriately consulted about quality principles and strategy in line with the Northern Ireland Courts and Tribunals Service’s Customer Service and Engagement Statement.
  • All statistical publications will contain a full description of data quality issues relating to release; and any impact that has on analysis of changes over time; or comparisons between different groups will be transparent to a lay and expert audience;
  • All statistical publications will be fully compliant with the published Revisions Policy;
  • All publications will have specific details as to how they are applying the Revisions Policy;
  • Survey data will be presented with full information on sampling variability; confidence intervals; response rates and other relevant criteria to allow users to make informed judgements on quality;
  • Administrative data will be published with details of how it is collected to allow users to understand its strengths and limitations.
Timeliness and Punctuality
  • All publications will comply with the Code of Practice on pre-announcement dates of publications;
  • We will publish statistical releases as soon as possible after the relevant time-period;
  • Statistical publications will be produced in line with our Customer Service and Engagement Statement.
Accessibility and Clarity
  • Statistical publications will published in line with the Northern Ireland Courts and Tribunals Service’s policy for internet publications;
  • All publications will use plain English wherever possible.
  • We will use harmonised concepts and definitions wherever they are available;
  • Any statistical publication which does not use harmonised definitions will clearly explain why the harmonised definition has not been used and any plans to move it on to a harmonised basis.
  • As standard practice we will release statistical publications on the same day in order to aid user understanding unless:
  • This would mean significant delay to one set of published figures in order to present the coherent set of releases;
  • User Engagement suggests that separate releases on separate days would be preferable.