These indicators complement those in table 1.3, which measure progress toward international goals for social and economic development. Except for the adult illiteracy rate, all of the indicators shown here appear elsewhere in the World Development Indicators.
Literacy is difficult to define and to measure.
To measure literacy using such a definition requires census or sample survey measurements under controlled conditions. In practice, many countries estimate the number of illiterate adults from self-reported data or from estimates of school completion. Life expectancy at birth is the number of years a newborn infant would live if prevailing patterns of mortality at the time of its birth were to stay the same throughout its life. Prevalence of child malnutrition is the percentage of children under 5 whose weight by age is less than minus two standard deviations from the median of the reference population. Access to sanitation is the percentage of the population with excreta disposal facilities that can effectively prevent human, animal, and insect contact with excreta.