This page describes under which circumstances data in the UIS Data Centre can change.
Section 1 summarizes the reasons for updates and revisions of the Data Centre. Section 2 summarizes the frequency of updates and revisions.
1. Reasons for updates and revisions of the UIS Data Centre
There are a number of reasons why data in the UIS Data Centre may be updated or revised:
1. New or revised data reported by countries
2. New or revised data provided by other international organizations
3. New or revised data from other sources
4. Correction of data errors
5. Methodological changes in the calculation of indicators
6. Changes in classifications
7. Changes in country groupings
1.1 New or revised data reported by countries
The UIS carries out annual surveys on education, literacy and educational attainment, science and technology, and culture and communication. After each survey, new data reported by countries are processed by the UIS and added to the UIS Data Centre, usually at the time of a scheduled data release (see UIS release calendar). Data reported by countries to partner organizations of the UIS, including Eurostat and OECD, are added to the Data Centre at the same time as data received directly from countries that respond to UIS surveys.
1.2 New or revised data provided by other international organizations
Many UIS indicators rely on complementary data collected by other international organizations, for example population data by the United Nations Population Division, labour force data by the International Labour Organization, or economic data by the World Bank. Revisions to these external datasets take place at regular intervals that are known in advance, between three times per year and once every two years. Changes in external datasets, for example population estimates by the UN Population Division, can result in revised values of UIS indicators although national data reported to the UIS may remain unchanged. New data received from external sources are usually updated in the UIS Data Centre at the time of a scheduled data release.
1.3 New or revised data from other sources
In addition to data reported by countries and other international organizations, the UIS disseminates data extracted from other sources of data. For example, literacy rates may be obtained from national household surveys or censuses. Other data, for example on science and technology or feature films, may be obtained from publications and revised if published figures change. Such data are usually added to the UIS Data Centre at the time of a scheduled data release.
1.4 Correction of data errors
Although the UIS has processes in place to minimise errors in its database, occasionally mistakes occur. If data which have been disseminated in the UIS Data Centre are found to be erroneous, they are corrected or removed. Corrections are usually made at the time of a scheduled data release but may also occur between scheduled releases.
1.5 Methodological changes in the calculation of indicators
The UIS occasionally improves the methods used to calculate an indicator. Such changes in methodology can result in revised data for all countries and all years for a given indicator. The revised data are usually added to the UIS Data Centre at the time of a scheduled release.
1.6 Changes in classifications
Changes in a classification – for example the International Standard Classification of Education (ISCED), which was revised in 2011 – can require a revision of data disseminated by the UIS. Reclassification of national education programmes, for example, can lead to changes in data reported by a country to the UIS. The revised data are usually added to the UIS Data Centre at the time of a scheduled release.
1.7 Changes in country groupings
Changes in country groupings, for example when a low-income country is reclassified as a middle-income country, affect the calculation of regional averages, which are usually updated once a year.
2. Frequency of updates and revisions of the UIS Data Centre
2.1 Scheduled updates
The UIS Data Centre is updated several times per year at the time of scheduled data releases (see UIS release calendar). Regional and global averages, for example for R&D or education data, are only updated once a year. Most changes of data in the Data Centre occur at the time of a scheduled data release.
2.2 Unscheduled revisions
Occasionally, data in the UIS Data Centre are updated between scheduled data releases. The most common reason is correction of data errors.
Last update: 29/1/2013