Official statistics: corporate policy statement on Quality

Aim

Principle 4 Practice 4 of the Code of Practice for Official Statistics requires that producers of Official Statistics to publish quality guidelines for their official statistics.

This document outlines the quality guidelines for the Scottish Government as considered along the European Statistical System’s six dimensions of quality. These are the relevance, accuracy, timeliness, accessibility and clarity, comparability and coherence of the statistics we collect, analyse and report.

It is expected that each topic area will produce a standalone quality document for their official statistics publications, under the provisions of the Code of Practice.

Quality Guidelines

Relevance

The degree to which the statistical output meets user needs for both coverage and content.

Key aspects

Any assessment of relevance needs to consider:

• who are the users of the statistics
• what are their needs
• how well does the output meet these needs

What users can expect

• to be appropriately consulted about their needs. The SG will seek to review data collections and statistical outputs on an ongoing basis to ensure that they continue to meet user needs
• to be engaged and informed through the Scotstat user consultation network

Accuracy

For survey data: the closeness between an estimated result and the (unknown) true value. For all data sources: how well the information is recorded and transmitted.

Key aspects

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
• model assumption error
• completeness
• timeliness of recording and transmission
• accuracy of recording of data items
• correct use of coding
• correct interpretation.

What users can expect

Survey data in SG publications will be presented with full information on:

• sampling variability
• confidence intervals
• response rates
• other relevant criteria to allow users to make informed judgments on quality.

All statistical publications will:

• include details of how the underlying data are collected to allow users to understand the strengths and limitations
• contain a description of data quality issues and any impact this may have on analysing changes over time
• be compliant with the published SG Revisions Policy or the specific policy for that output
• ensure that comparisons between different groups will be transparent to both lay and expert audiences

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.

Key aspects

An assessment of timeliness and punctuality should consider the following:

• production time
• frequency of release
• punctuality of release

What users can expect

Publications will comply with the Code of Practice on pre announcing dates or will state clearly at the time of pre announcement any reasons why this has not been followed.

We will publish Statistical releases as soon as possible after the relevant time period.

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.

Key aspects

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

What users can expect 

Statistical publications will be published in line with the SG website’s accessibility policy. All publications will use Plain English wherever possible.

Comparability

The degree to which data can be compared over time and domain.

Key aspects

Comparability should be addressed in terms of comparability over:

• time
• spatial domains e.g. sub-national, national, international
• domain or sub population e.g. crime/offence type, ethnicity.

What users can expect

We will use harmonised concepts and definitions in statistical publications wherever they are available. Any statistical publication which does not use harmonised definitions will explain why this has not been used and any plans to move it onto a harmonised basis.

Coherence

The degree to which data derived from different sources or methods but which refer to the same phenomenon are similar.

Key aspects

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
• data published at different geographic levels
• definitions and coding used for different data sources

What users can expect

As standard practice, we will release related statistical publications on the same day in order to aid user understanding unless: This would mean significant delay to one set of figures in order to present the coherent set of releases or user engagement suggests that separate releases on separate days would be preferable. Where related measures are published across several publications we will make it clear to users where the related information can be found.