Last study on effective learning time and teacher attendance (year)
The data derived from national sources may differ from international sources because of divergences in definitions, methods of calculation, or in some cases due to different underlying data.  For these reasons, the data based on national sources in this database should not be used for making comparisons between countries, but rather for assessing the progress of individual countries.
Date (year) of the most recent study carried out by any national or international entity on the effectiveness of the instruction time devoted to learning activities.