Teachers complete the Australian version of the Early Development Instrument for each child in their class. The Instrument is made up of about 100 questions. The responses provide information on the five domains: physical health and wellbeing, social competence, emotional maturity, language and cognitive skills (school-based), and communication skills and general knowledge. Data is collected for individual children and then reported for a group of children at a community, state/territory and national level.
Responses for each child on the Instrument are combined to determine an AEDC domain score. Five domain scores are calculated for each individual child, where sufficient data are collected.
To determine whether an individual domain score is 'developmentally on track', 'developmentally at risk' or 'developmentally vulnerable', national 'cut-offs' were established during the first national data collection in 2009.
To create the national cut-offs in 2009, all the children's domain scores were ranked from lowest to highest. Scores ranked in the lowest 10 per cent were classified as developmentally vulnerable. Scores ranked between 10 per cent and 25 per cent were classified as developmentally at risk. Scores ranked in the highest 75 per cent were classified as developmentally on track.
These national cut-offs have been applied to all data collections, to provide a reference point to track children's developmental outcomes across Australia over time through the AEDC programme.
Information about the previous three data collections is available in the AEDC Data Guidelines and the AEDC Data Dictionary.