1. Glossary

School year and holiday periods

Beginning of the school year

The period from the first official day of school (it may not necessarily be the first day of instruction), as defined in official/steering documents.

Holiday period

A holiday period consists of days when students are not required to be present at school (compared to the usual school week). Examination periods (even if taken outside the schools), teacher training days, school trips when some or all students are not present at school are NOT part of the holiday period, even if only some students are required to attend. 
No distinction is made between school holidays and public holidays. Moreover, public holiday that falls during a weekend is not considered as a holiday. 
The definition of weekends varies across countries. They often refer to Saturday and Sunday but, in some countries, they may be limited to Sunday. The weekend following the last day of the holiday period is considered as part of the holiday period if the holiday period ends on the last school day of the week. 
When the length of summer holidays varies for one grade within a specific ISCED level, this specific duration is considered as an exception and therefore not reported.
Only breaks of at least 7 consecutive days are considered. 

Decision-making levels

Top-level authority

'Top-level authorities' refers to all government bodies at the national (state) level that make or participate in different aspects of decision-making. In 'federal' countries, or countries with a similar type of government structure, they refer to the first level of territorial authority immediately below the national level. The highest level of authority with responsibility for education in a given country is usually located at the national (state) level. However, for Belgium, Germany and Spain, the communautés , Länder and comunidades autónomas, respectively, are responsible for all or most areas relating to education. Therefore, these administrations are considered the top-level authority for the areas where they hold the responsibility, while for the areas where they share the responsibility with the national (state) level, both are considered to be top-level authorities.

Regional/provincial level

It refers to the first level of territorial authority immediately below the national level in countries that do not have a 'federal' or similar type of governmental structure, and they refer to the second level of territorial authority below the national government in countries with a 'federal' or similar type of governmental structure.

Local level 

It refers to the lowest level of territorial authority in a nation. The local authority in terms of education may be the education department within a general-purpose local government or a special-purpose local government body where the sole area of responsibility is education.

School level

It refers to the decision-making bodies located within the school, which could be: (1) an external school board, which includes residents of the wider community; (2) an internal school board, which could include school heads, teachers, other school staff, parents and students; and (3) both an external and an internal school board. 'School networks', 'networks of schools', 'didactic circles' and 'groups of schools' or 'school clusters' are considered as school-level authorities.

2. International Standard Classification of Education (ISCED 2011)

This data collection covers primary and general (lower and upper) secondary education. The definitions used are those set down in the 2011 International Standard Classification of Education (ISCED).

Primary education (ISCED 1)

Programmes at this level are typically designed to provide students with fundamental skills in reading, writing and mathematics (i.e. literacy and numeracy), and to establish a solid foundation for the learning and understanding of core areas of knowledge in preparation for lower secondary education. They also seek to promote children's personal and social development. Age is typically the only entry requirement at this level. The customary or legal age of entry is usually between 5 and 7 years old. This level typically lasts 6 years, although its duration can range between 4 and 7 years, depending on the country. 

General lower secondary education (ISCED 24)

Programmes at the lower-secondary level (ISCED 2) are typically designed to build on the learning outcomes from ISCED level 1. Students typically enter this level between the ages of 10 and 13 (age 12 being the most common). The ISCED designator 24 denotes general lower secondary education.

General upper secondary education (ISCED 34)

Programmes at the upper secondary level (ISCED 3) are typically designed to complete secondary education in preparation for tertiary education or to provide skills relevant to employment, or both. Pupils typically enter this level between the ages of 14 and 16 years. The ISCED designator 34 denotes general upper secondary education.