Private enrolment refers to pupils or students enrolled at a given level of education in institutions that are not operated by a public authority but controlled and managed, whether for profit or not, by a private body, such as a non-governmental organisation, religious body, special interest group, foundation or business enterprise.

GER is the ratio of total enrolment, regardless of age, to the population of the age group that corresponds to the same level of education. GER can exceed 100% due to the inclusion of over-aged and under-aged students, because of early or late school entrance, and grade repetition. For the tertiary level, the population used is the 5-year age group starting from the official secondary school graduation age (Source: UIS, Education Indicators - Technical Guidelines: p.9)

According to international human rights law, non-government schools must conform to minimum educational standards, as laid down or approved by the State. Minimum educational standards may relate to issues such as admission, curricula and the recognition of certificates

Percentage of students at the lowest level of science proficiency is the percentage of students at the lowest level of proficiency on the science scale in national or international assessments

Percentage of students at the lowest level of mathematics proficiency is the percentage of students at the lowest level of proficiency on the mathematics scale in national or international assessments

Percentage of students at the lowest level of reading proficiency is the percentage of students at the lowest level of proficiency on the reading scale in national or international assessments