They are involved in an Australian-first program called The Little School, which takes place in a replica school and helps children with autism transition into prep.

Starting school can be a particularly confronting experience for the increasing number of children diagnosed with autism.

Classroom noise, simple instructions and participating in group activities can present huge challenges.

The pre-prep program – which will run out of Autism Partnership Australia's headquarters in North Melbourne from Monday – hopes to eliminate these challenges.

"Starting school can be tricky," Autism Partnership Australia managing director Shannon Eeles said.

"They have to learn all the regular things that typical kids have to learn, as well as social skills. We are hoping to teach some of these important skills before the kids start school."

Groups of six children work with a teacher and two behaviour therapists in a sunny open-plan classroom with whiteboards, lockers and colourful wall charts.

There's even a mock canteen, where the four and five-year-olds practise ordering and buying lunch.

Social skills underpin everything that is taught in the program.

As well as learning how to work in groups and the nuances of interacting with friends, they will learn how to decipher a teacher's instructions. They will go over the routines of school over and over again.

Towards the end of the program, which mimics the school terms, the teachers will start working with the children's new mainstream schools.

"Our goal is for them to leave here as independent as possible," Ms Eeles said.

When the children first accessed early intervention services three years ago, many did not speak or enjoy interacting with their peers.

But these days, they look like any other four and five-year-old.

As they sit on a rainbow mat in the classroom, Jack, a bubbly five-year-old, points at a flashcard his teacher is holding and shouts "cows make milk!"

But this sort of support is not cheap: the annual cost of the pre-prep program is $39,500 for five half-days a week.

Professor Cheryl Dissanayake, who directs Latrobe University's Olga Tennison Autism Research Centre, said an increasing awareness of autism, and a broadening of its definition, had led to more children being diagnosed with the disorder.

About 2 per cent of children who start school have been diagnosed with autism, Dr Dissanayake said.

Autism affects the way the brain processes information, and children with autism may struggle to communicate and interact with their peers.

When a child with autism displays negative behaviours in the classroom, it is usually because they are struggling to communicate, Dr Dissanayake said.

She said better training for teachers and more teaching aids, speech pathologists and behaviour therapists would increase these students' chances of success in school.

"Staff are not sufficiently trained or supported and it can lead to unhappy situations where children are not succeeding in the classroom, or being excluded. Many end up being home-schooled."

She said early-intervention services should be funded by the National Disability Insurance Scheme to reduce costs further down the track.

"If the costs are covered in those early years, these children will be able to learn, and give back to the community and they won't need welfare support."

The state government is conducting a review of its program for students with disabilities, with the findings expected to be presented to Education Minister James Merlino in coming months.

For more information: autismpartnership.com.au