EXAMINERS have admitted that a computing exam sat by thousands of Scottish pupils contained coding errors.

This summer’s National 5 computing science exam provoked a backlash from teachers who said it was of the worst ever set.

In the immediate aftermath the Scottish Qualifications Authority (SQA) denied there was a problem saying feedback had been positive.

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When the issue was raised at the Scottish Parliament the body then admitted to “a small number of typographical errors”.

Now an official report into the exam by SQA experts has revealed there were “coding errors” in the exam as well as mistakes in the way questions were worded.

The report highlighted a particular problem with one question stating it “contained an error which did not allow this question to be answered as it was originally designed”.

It also reveals that, after marking the exam, the SQA adjusted the boundaries between grades to ensure no candidates were disadvantaged.

The admission comes months after computing science specialists launched an outspoken attack on the qualification highlighting problems with 19 out of the 21 questions.

Teachers described the paper as one of the worst ever set and called for the SQA to hold an inquiry.

Critics highlighted confusing questions, questions with multiple possible answers and some where knowledge would have been required from outside the course, such as the legislation around cloning of phones.

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Following the concerns the issue was raised in the Scottish Parliament and John Swinney, the Education Secretary, told MSPs he had “made clear his discontent”.

He added: “I think, frankly, that is not good enough, these issues should be checked properly, there is adequate opportunity for this to be done and I have made clear my discontent about that to the chief examiner.”

The controversy comes at a difficult time for computing science in schools with falling teacher numbers and concern the importance of the subject to the future economy is being ignored.

In 2014 it was revealed that the number of computing science teachers in Scotland has dropped sharply, sparking fears for the future of the subject. One in eight secondary schools in Scotland does not have a computing science specialist at all.

The concerns about the National 5 computing science paper came to light in a number of internet forums used by specialist teachers.

One teacher from a high profile Edinburgh private school described the paper as “the most error-strewn and, in places, incomprehensible examination I’ve seen in my career”.

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He said: “It contains typos, incorrect code and other errors which make questions unanswerable.

“It is strewn with grammatical errors, it requires knowledge which is not in the course and some questions are so poorly designed and worded even the most able of candidates could well be defeated by them. There has clearly been insufficient quality assurance.”