The duration of each level of education can vary greatly across countries. These differences can lead to problems when attempting to compare statistics across countries. The International Standard Classification of Education (ISCED) is the official framework used to facilitate international comparisons of education systems. It was developed in 1976 by the United Nations Educational, Scientific and Cultural Organization (UNESCO) and was revised in 1997 and 2011. EdStats uses indicators based on the ISCED 2011 classifications listed below: ISCED 0 = Early childhood education ISCED 1 = Primary Education ISCED 2 = Lower Secondary Education ISCED 3 = Upper Secondary Education ISCED 4 = Post-secondary non-Tertiary Education ISCED 5 = Short-cycle tertiary education ISCED 6 = Bachelors degree or equivalent tertiary education level ISCED 7 = Masters degree or equivalent tertiary education level ISCED 8 = Doctoral degree or equivalent tertiary education level For more information on the IS...