Canberra principals have warned that raising the bar on what students can be suspended for will make it more difficult to manage their behaviour.

Key points: ACT Education Directorate says suspensions have "limited effectiveness"

ACT Education Directorate says suspensions have "limited effectiveness" Principals Association boss argues raising the bar for suspension could harm victims

Principals Association boss argues raising the bar for suspension could harm victims Parents and Citizens Council claims suspensions could have opposite effect to what is hoped

The ACT Government is considering changes to school suspensions that would change what behaviours qualify for suspension, and introduce extra steps before a student is suspended.

"It's really clear that suspension is not always going to result in the end point that we would like," Student engagement director Sam Seton said.

"It's really about how we support our young people in changing their behaviours, rather than just punishing behaviours."

The proposed changes would leave suspensions as a tool of last resort, only to be used after other methods such as restorative justice are exhausted.

It would also redefine suspensions as a tool to be used primarily in cases of occupational violence or where someone's safety was endangered.

"The key points for suspensions are around safety for our young people and the people around them," Ms Seton said.

But ACT Principals Association head Michael Battenally said suspensions were still effective for managing behaviour, and most instances were one-offs that sent a clear message.

"In a civil society there are limitations with a school about what punitive measures you have in play to set the tone, set the culture of expectations," he said.

"It is a concern if that does raise, we lessen the capacity of principals to suspend."

Mr Battenally also warned it may be a disservice to victims if an offender was not adequately punished.

"Suspension is not just about the offender, it's about victims," he said.

"If you had a child at school and that child was in a situation where they were assaulted … you would expect and would hope their needs were being met through the outcome as much as the student who was the offender."

The Parents and Citizens Council has backed the new suspensions policy.

Its policy director, Veronica Elliott, said in some cases suspensions may cause a student to further disengage.

"People still see suspension as a really clear, serious message. I think we recognise now though that sometimes, in a small number of instances, suspension is not actually supporting behavioural change in some students," Ms Elliott said.

"It's really important that before those students disengage from school completely to look for other ways to engage with them."

Ms Seton said each student needs to be considered individually, and suspensions may be one element of managing a student’s behaviour.

"What we really want to do is reduce the incidence of behaviour that could lead to suspensions," Ms Seton said.