About the data
Definitions
Data sources
Indicators of persistence or grade progression provide a measure of how successful an education system is in maintaining a flow of students from one grade to the next and thus of imparting a particular level of education. Although school attendance is mandatory in most countries, at least through the primary level, students drop out of school for a variety of reasons; discouragement over poor performance, the cost of schooling, and the opportunity cost of additional time spent in school are frequently cited. In addition, the progress of students to higher grades may be limited by the availability of teachers, classrooms, and educational materials.
Persistence measures the proportion of a single-year cohort of students that eventually reaches a particular grade or level of schooling. Tracking data for individual students are not available, so calculations are based on the reconstructed cohort method. This method uses data on average promotion, repetition, and dropout rates to calculate the flow of students from one grade to the next. Other flows caused by new entrants, reentrants, grade skipping, migration, or school transfers during the school year are not considered. The reconstructed cohort method makes three simplifying assumptions: dropouts never return to school; promotion, repetition, and dropout rates remain constant over the entire period in which the cohort is enrolled in school; and the same rates apply to all pupils enrolled in a given grade, regardless of whether they previously repeated a grade.
Because UNESCO data do not include dropouts or dropout rates, the number of dropouts was estimated as the difference between enrollments in successive grades in successive years, after netting out repeaters. The remaining students are assumed to be promoted. Repeated application of the same calculations leads to an estimate of the number of students entering each successive grade (Fredricksen 1991).
The percentage of the cohort reaching grade 4, rather than some other grade, is shown for two reasons. First, because of differences among countries in the duration of primary schooling, which ranges from three to 10 grades (see table 2.7 for each country's duration of primary schooling), grade 4 estimates are more comparable across countries than are estimates for other grades. Second, using grade 4 minimizes the effect of repetition at or close to the final grade of primary education.
Progression to secondary school measures the proportion of students in the final grade of primary school who enter the first year of the general secondary system. The comparability of this indicator across time and between countries may be affected by changes in the definition of the primary and secondary levels, rules governing repetition and promotion, and the availability of special programs and other alternatives to the general secondary education system. Enrollment in the final grade of primary school may be systematically overestimated because enrollment as reported at the beginning of the school year includes dropouts who may leave school during the year.
Expected years of schooling estimates the total number of years of schooling that an average child will receive. It may also be interpreted as an indicator of the total education resources, measured in school years, that a child will require over his or her "lifetime" in school. Because the calculation of this indicator assumes that the probability of a child's being enrolled in school at any future age is equal to the current enrollment ratio for that age, changes and trends in future enrollment ratios are not accounted for.
• Percentage of cohort reaching grade 4 is the proportion of children enrolled in primary school in 1980 and 1990 who reach grade 4 in 1983 and 1993, respectively. The estimate is based on the reconstructed cohort method (see About the data).
• Progression to secondary school is the number of new entrants in the first grade of secondary (general) school divided by the number of children enrolled in the final grade of primary school in the previous year (according to the country's duration of primary education, as shown in table 2.7).
• Expected years of schooling are the average number of years of formal schooling that a child is expected to receive, including university education and years spent in repetition. They are the sum of the age-specific gross enrollment ratios for primary, secondary, and tertiary education.
Estimates of the percentage of cohort reaching grade 4 and progression to secondary school were compiled using the UNESCO database on enrollment by level, grade or field, and gender. Data on expected years of schooling are from UNESCO's Statistical Yearbook, supplemented by information from UNESCO's World Education Report.