Technical Notes: Education and Literacy VARIABLE DEFINITIONS AND METHODOLOGY: Primary School Education is defined by the International Standard Classification of Education (ISCED) as the "beginning of systematic apprenticeship of reading, writing and mathematics". Programs are typically six years long and represent the beginning of compulsory education in many countries. Secondary School Education follows primary education, and is characterized by the ISCED as being subject-oriented with specialized fields of learning. Programs may be vocational or technical in nature, and students achieve a full implementation of basic skills. Tertiary School Education, as characterized by the ISCED, provides the level of education required for entry into an advanced research program or a profession with high skills requirements. Faculty are typically required to have advanced research credentials. A broad variety of tertiary education programs exist in different countries. Net Enrollment Ratio (NER) is defined as the enrollment of the official age-group for a given level of education expressed as a percentage of the population from the same age group. The theoretical maximum value is 100%, but inconsistencies with enrollment age data as the NER approaches 100% may produce values greater than 100% (see cautionary notes below). A high NER denotes a high degree of participation of the official school-age population. If the NER is below 100%, users should not assume that the remaining school-aged population is not enrolled in any school; they could be enrolled in school at other grade levels. Gross Enrollment Ratio (GER) is defined as the total enrollment, regardless of age, expressed as a percentage of the official school-age population for a given level. Gross enrollment ratio can be over 100% due to the inclusion of over-aged and under-aged students. Gross enrollment ratios show general levels of participation in education. When net (aged-based) enrollment data are not available, gross enrollment can be used as a substitute indicator. This data can also be compared to net enrollment figures to indicate the extent of over- and under- aged enrollment. Gross enrollment ratios of 100% or more indicate that a country is, in principle, able to accommodate all of its school-age population. Youth Literacy Rate is defined as the percentage of the population aged 15 to 24 years old who can both read and write, with understanding, a short, simple statement about their everyday life. Youth literacy rates are increasingly used to gauge the impact of primary education as well as the speed with which illiteracy can be eradicated. In general, literacy data can measure the achievement of literacy programs and primary education. Adult Literacy Rate is defined as the percentage of the population aged 15 years and over who can both read and write, with understanding, a short, simple statement about their everyday life. In general, literacy data can measure the achievement of literacy programs and the effectiveness of primary education. Information on the methodologies used to collect these data can be found in the technical notes for each variable in the EarthTrends searchable database, at http://www.earthtrends.org. FREQUENCY OF UPDATE BY DATA PROVIDERS: Enrollment: UNESCO data are available from WRI for each year from 1980-1998 and every 5 years from 1960 to 1980. Some data are available for 1999. The year of the data indicates when a school year started; 1998 data, for example, are for the 1998-1999 school year. UNESCO updates the data regularly as new estimates are made available; as of summer 2003, data thru 2001 were available for some countries at the UNESCO website. Literacy: Data are available annually from 1980 to 2002. UNESCO updates the data regularly as new estimates are made available. The most recent updates were in January, 2002. DATA RELIABILITY AND CAUTIONARY NOTES: Enrollment: While UNESCO keeps the most complete global data set on enrollment levels, problems do remain. The availability and quality of national school enrollment statistics vary widely, particularly for developing countries. Even though UNESCO has applied the same methodology to analyze all of the country data, definitions of "schooling" and "enrollment" are not strictly comparable among countries. As net enrollment ratios approach 100%, inconsistencies with enrollment and/or population data are more likely to skew the resulting ratios. As a result, some net enrollment ratios are greater than 100%. Difficulties arise when a substantial proportion of students begin school earlier than the prescribed age, or when the reference date for entry into primary education does not coincide with the birthdays of all eligible students. Literacy: While the empirical results of a 1994 assessment by UNESCO confirmed that most countries adhere to the standard definition of literacy identified above and that statistics are consistent enough to compare among countries, problems do remain. The availability and quality of national statistics on literacy vary widely, particularly for developing countries. When census and survey data are not available for a particular country, estimates need to be made based on neighboring countries. Even when census and survey data are available, they are typically collected only once every decade. Many industrialized countries have stopped collecting literacy data in recent years, based on the sometimes incorrect assumption that universal primary education means universal literacy. In addition, UNESCO's definition of literacy does not include people who, though familiar with the basics of reading and writing, do not have the skills to function at a reasonable level in their own society. Practices for identifying literates and illiterates during actual census enumeration may also vary, and errors in literacy self-declaration can affect data reliability. Some countries, for example, may equate persons with no schooling for illiterates, or change definitions between censuses. SOURCES: Enrollment: United Nations Educational, Scientific, and Cultural Organization (UNESCO) Institute for Statistics. 2002. World Education Indicators. Paris: UNESCO. Literacy: United Nations Educational, Scientific, and Cultural Organization (UNESCO) Institute for Statistics. 2002. Special Estimates and Projections of Adult Illiteracy for Population Aged 15 Years Old and Above, By Country and By Gender. Paris: UNESCO. Available online at: http://www.uis.unesco.org/en/stats/stats0.htm. United Nations Educational, Scientific, and Cultural Organization (UNESCO) Institute for Statistics. 2002. Special Estimates and Projections of Adult Illiteracy for Countries With No Census Data. Paris: UNESCO. Available online at: http://www.uis.unesco.org/en/stats/stats0.htm.