Eurostat defines the quality of statistics with reference to six criteria:
1. Relevance: an inquiry is relevant if it meets users' needs. The identification of users and their expectations is therefore necessary. In the European context, domains for which statistics are available should reflect the needs and priorities expressed by the users of the European Statistical System (completeness).
2. Accuracy: accuracy is defined as the closeness between the estimated value and the (unknown) true value.
3. Timeliness and punctuality in disseminating results: most users want up-to-date figures which are published frequently and on time at pre-established dates.
4. 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.
5. 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.
6. 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.