Stand-downs, suspensions, exclusions and expulsions are measures of a school’s reaction to challenging behaviour. While one school may opt to suspend a student over a particular incident, another school may not. The number of these incidents should not be used as a proxy measure for student behaviour. This indicator uses age-standardised rates. These are expressed as the number of stand-downs, suspensions, exclusions and expulsions per 1,000 students enrolled. (Most stand-downs, suspensions and exclusions occur between the ages of 13-15). Age-standardisation allows a fair comparison between different cohorts. In any given year the schooling population will have a different age distribution. By standardising for age we can compare across years.