Definition: Quality

Category: International guidelines on statistical business registers

ISO standard 9000:2000 states that quality is the "degree to which a set of inherent characteristics fulfills requirements". Therefore the quality of statistics can be determined by the extent to which they meet user needs.

Quality of statistics can be defined with reference to several criteria.

- Relevance: an inquiry is relevant if it meets users’ needs. The identification of users and their expectations is therefore necessary.

- Accuracy: accuracy is defined as the closeness between the estimated value and the (unknown) true value.

- Timeliness and punctuality in disseminating results: most users want up to date figures which are published frequently and on time at pre-established dates.

- Accessibility and clarity of the information: statistical data have most value when they are easily accessible by users, are available in the forms users desire and are adequately documented.

- Comparability: statistics for a given characteristic have the greatest usefulness when they enable reliable comparisons of values taken by the characteristic across space and time. The comparability component stresses the comparison of the same statistics between countries in order to evaluate the meaning of aggregated statistics at the European level.

- Coherence: when originating from a single source, statistics are coherent in that elementary concepts can be combined reliably in more complex ways. When originating from different sources, and in particular from statistical surveys of different frequencies, statistics are coherent in so far as they are based on common definitions, classifications and methodological standards.

- Completeness: domains for which statistics are available should reflect the needs and priorities expressed by the users of the European Statistical System http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=42180 Eurostat, "ESS Handbook for Quality Reports", Luxembourg: Office for Official Publications of the European Communities, 2009