Unlike most other large-scale learning assessments, ASER is a household-based rather than school-based survey. This design enables all children to be included – those who have never been to school or have dropped out; those who are in government schools, private schools, religious or other types of schools; as well as those who are absent from school on the day of the assessment. In the ‘basic’ ASER design, 30 villages are sampled in each rural district from the most recent Census village directory. In each village, 20 randomly selected households are surveyed. This process generates a total of 600 households per district or about 300,000 households for the country as a whole. Approximately 600,000 children aged 3-16 residing in these households are surveyed. See the process documents page for more information.