This data collection focuses on the salaries of teachers and school heads in public educational institutions. However, in a few countries, the reported salaries may also apply to government- dependent private schools.

According to the 2016 United Nations Educational, Scientific and Cultural Organization, OECD and Eurostat (UOE) manual for the data collection on education systems, an education institution is classified as public or private depending on whether it is under the overall control of a public or private body.

An institution is classified as public if it is controlled and managed directly by a public education authority or agency; or controlled and managed either by a  overnment agency directly or by a governing body (council, committee, etc.), the majority of the members of which are either appointed by a public authority or elected by the public.

An institution is classified as private if it is controlled and managed by a non-governmental organisation (e.g. a church, a trade union or a business enterprise, a foreign or international agency), or its governing board consists mostly of members not appointed by a public agency.

The terms ‘government dependent’ and ‘independent’ refer only to the degree of a private institution’s dependence on funding from government sources; they do not refer to the degree of government direction or regulation. A government-dependent private institution is one that either receives at least 50 % of its core funding from government agencies or one where its teaching staff are paid by a government agency – either directly or through the government. An independent private institution is one that receives less than 50 % of its core funding from government agencies and whose teaching staff are not paid by a government agency.

This data collection covers fully qualified, full-time teachers and school heads. Part-time teachers and those that are not yet fully qualified are beyond the scope of the study.

Fully qualified teachers are those who have fulfilled all the training requirements for teaching (one or more subjects) and meet all other official requirements (e.g. probation period). Their professional tasks involve the planning, organisation and delivery of group or individual activities for a class of students with respect to the development of their knowledge, skills and attitudes.

The designation ‘full-time teacher’ is usually based on statutory working hours, as opposed to actual total working time or actual teaching time. A teacher employed for at least 90 % of the normal or statutory number of hours of work for a full-time employee over a complete school year is considered as a full-time teacher in the context of this survey.

The term school head refers to any person whose primary or major function is heading a school or a group of schools alone or within an administrative body such as a board or council. The school head is the primary leader responsible for the leadership, management and administration of the school.

Depending on circumstances, school heads may exercise educational responsibilities (which may include teaching tasks, but also responsibility for the general functioning of the institution in areas such as the timetable, implementation of the curriculum, decisions about what is to be taught and the materials and methods used). They may also have, to a varying degree, other administrative, staff- management and financial responsibilities.