Year 11 students, or fifth-formers as they would have been known had they been enrolled just a year earlier, first walked through the doors of the newly christened Dickson, Phillip (now Canberra), Stirling, Narrabundah and Hawker colleges in 1976.

The Class of 1976 was the last to take the Higher School Certificate in Canberra, with the ACT Schools Authority replacing the system with a new structure encouraging the colleges to set their own courses and bridge a middle ground between rigid high school learning and the maturity of tertiary education.

The anniversary was pointed out in a letter to The Canberra Times from retired teacher Ian Foster, who was the senior science teacher at Hawker College from 1978 to 1984, the student services teacher at Lake Ginninderra College from 1991 to 2001 and a former ACT Board of Senior Secondary Studies member and assistant technical adviser.

He wrote that the push to introduce secondary colleges was hard-fought, with constant reviews in the early years and criticism from several sectors of the community.

"They courageously confounded the critics who did not accept that adolescents would respond positively to being treated as mature young people, that schools could involve parents and employers in curriculum design, that teachers were capable of both teaching and assessing students and that, despite this upheaval, university entry was still possible," he wrote.

"Canberra's educational leaders saw a window of opportunity and amalgamated Tasmania's successful matriculation colleges and Queensland's innovative school-based assessment system."

The change was not without its problems, however; a February 2, 1976 report in The Canberra Times revealed large parts of Phillip College had not been completed in time for opening day.

"In one area, students will have to walk under scaffolding piled with planks and ladders to get to class," the report said. Classes were delayed for a week.

When the plans were first proposed in 1974 to convert Dickson High School into a college, its P&C protested the decision alongside several other high schools.

Meanwhile, Australian National University philosophy lecturer Dr Richard Campbell warned a public meeting in September that year about thinking "we have arrived at a point to rest in", as well as suggesting alternative education methods would only be possible with existing resources.

Staff cut demands and the threatened closure of Narrabundah College due to low enrolments also dogged the system's first decade.

But Mr Foster said the changes had ultimately been positive and recognised nationally for its strengths.

"It's hard to contemplate the courage of those who advocated and then implemented such sweeping reforms, affecting the children of virtually their entire community."