Since 2005, the Federal Statistical Office has offered Quality Reports on all federal statistics. Through that medium, users are provided with standard-format information on the methods and definitions applied and on the quality of statistical results. Also, the quality reports contain information on other publications and contacts. Such additional information may be used by users to properly interpret the data and to better assess the information value of the data obtained.
The structure of the Quality Reports is based on the quality concept of the European Statistical System (ESS) and on the principles regarding the quality of statistical products according to the European Statistics Code of Practice. The statistical offices of the Federation and the Länder have dealt with the ESS quality concept and have adapted it to the quality reports.
Statistical data are produced for the users' requirements. The quality characteristic of "purpose and goals" is met by statistical data if they meet user requirements. In the ESS, that quality characteristic is referred to as "relevance".
The results of statistical surveys generally are not identical to the true values of the relevant population. The difference between the survey result and the unknown true value is referred to as the mean square error of the result. Generally, a distinction is made between sampling errors and non-sampling errors.
Most users of official statistics are interested in timely data. The timeliness of a statistics refers to the time difference between the reference date or the end of the reference period and the date when the statistical information is scheduled to become available to the users. Punctuality refers to the possible time lag between the actual delivery date of data and the target date at which they should be delivered.
Statistical results on the same items should be comparable, even if they refer to different populations. The comparisons may refer to international, regional, time or category differences. Differences may occur due to different survey concepts and measurement methods.
Statistical results referring to the same population, though coming from different statistics, should be coherent, i. e. it should be possible to put them in relation to each other without contradictions occurring. It should be possible to combine, and use together, related results from different sources. In the ESS, that quality characteristic is referred to as "coherence".
Such information sources refer to whether users can easily and rapidly access statistical data, whether they receive the data within an acceptable period according to usual standards and in the expected form and whether they are reasonably informed and supported regarding concepts and methods. In the ESS, that quality characteristic is referred to as "accessibility and clarity".
Our users are informed about the quality standards in German official statistics not only through the quality reports but also through a comprehensive brochure.
Further information on data quality is available on the homepage of the Statistical Office of the European Communities (Eurostat) and in the following documents.
The European Statistics Code of Practice.
Qualitätsberichte (Quality Reports) - A new range of information on methods, definitions and data quality of federal statistics. (Wirtschaft und Statistik 2/2006 - only in German).
© Statistisches Bundesamt, Wiesbaden 2014