What is quality?

The quality of a statistical product can be defined as the “fitness for purpose” of that product. More specifically, it is the fitness for purpose with regards to the European Statistical System dimensions of quality:

  • relevance – is the degree to which a statistical product meets user needs in terms of content and coverage
  • accuracy and reliability – is how close the estimated value in the output is to the true result
  • timeliness and punctuality – describes the time between the date of publication and the date to which the data refers, and the time between the actual publication and the planned publication of a statistic
  • accessibility and clarity – is the ease with which users can access data, and the quality and sufficiency of metadata, illustrations and accompanying advice
  • coherence and comparability – is the degree to which data derived from different sources or methods, but that refers to the same topic, is similar, and the degree to which data can be compared over time and domain, for example, geographic level

There are additional characteristics that should be considered when thinking about quality. These include output quality trade-offs, user needs and perceptions, performance cost and respondent burden, and confidentiality, transparency and security. More information on the use of these dimensions to measure statistical output quality can be found in the “Quality statistics in government” guidance. The quality of processes can be measured through efficiency, effectiveness, robustness, flexibility, transparency and integration.

ONS and quality

Our statistics are generally recognised as fit for purpose by our customers. The Code of Practice for Statistics requires us to continuously improve our engagement with customers on statistical quality by ensuring customers understand the quality of our statistics and by establishing how far the quality meets their needs. The Office for National Statistics (ONS) Statistical Quality Improvement Strategy sets out actions we can take to improve the quality of our statistics. Additional government security requirements and the continued concern about data assurance requires us to ensure our confidentiality commitments are met and that the security of our statistics is maintained. Establishing a climate of continuous quality improvement will also reduce cost and enhance value.

All of our statistics are official statistics but those statistics that comply with the Code of Practice for Official Statistics are designated “National Statistics”. More information on this can be found on the UK Statistics Authority’s “Types of Official Statistics” page.