The latest Programme for International Student Assessment (Pisa) rankings indicate Scotland’s worst-ever overall performance for reading, maths and science, suggesting that the country is far from being the world leader in education that it once was.

And it is little wonder. The Scottish education system has endured two decades of change, which many would say have taken us backwards instead of forwards. Just about everything that was introduced and lauded as “groundbreaking” and “world-class” has, in fact, been shown to be highly flawed.

The broad general education that pupils receive during their first two years of secondary school was expected to be reduced to one year to give pupils more time for their exam courses. Instead, it was extended to three years. It was an obvious blunder, which resulted in exam courses, with all their unit assessments and assignments, having to be completed within a year.

The pressure put on pupils and teachers was, and still is, considerable. In 2015, a study by the World Health Organisation concluded that Scottish 15-year-olds were among the most stressed in the world.

Scrapped at long last

Another major change was the introduction, in secondary schools, of faculty head posts in place of principal teachers, which resulted in more than a few subjects losing their specialist leaders. And this was at a time, with the launch of Curriculum for Excellence and new exam courses, when specialist principal teachers were most needed. The loss of these posts, many believe, has had a hugely negative impact on learning and teaching.

Unit assessments - the idea of insisting that each part of a course has to be passed before an overall award can be made - was a solution to a problem that didn’t exist. Most courses now have three unit assessments, but the initial change involved several times this number; I remember one pupil telling me that he had 29 assessments to pass for his five Higher courses.

Now, at long last, unit assessments are being scrapped, but they should never have been introduced in the first place.

‘A whole page could be devoted to other shortcomings in the changes introduced over the past two decades’

Teachers have not been well served by the Scottish Qualifications Authority and Education Scotland. Instead of providing easy-to-follow course guidelines and assessment procedures, they’ve distributed some of the most complicated, badly-written documents you will ever come across.

The 2016 exam for National 5 computing, with its numerous errors and poor wording, exemplified these failings.

A whole page could be devoted to other shortcomings in the changes introduced over the past two decades, including the “groundbreaking” chartered teacher scheme, which was quickly scrapped, and CfE, which still struggles to convince.

But perhaps the biggest frustration of all has been the diversion of funding away from teachers and resources into the hands of bureaucrats and consultants.

John Greenlees is a secondary teacher in Scotland