Nineteen out of 21 questions in the National 5 exam on May 27 contained problems, according to Computing at School Scotland, a group representing subject teachers.
Kate Farrell, executive committee member of the organisation, said members had identified a series of errors ranging from grammatical mistakes to unanswerable questions.
“We are concerned this will have affected the performance and shaken the confidence of many candidates,” she said.
“We understand writing an exam paper is a collaborative process, and one that involves teachers who write questions for the paper, but we are greatly concerned that the current method of writing exam papers does not include sufficient quality assurance leading to duplication and errors.”
The SQA should carry out a review of its exam writing process to ensure such mistakes do not happen again, Ms Farrell said.
Typographical errors were rife. One question read: “Give one reason of using this type of selection” while in another question the weight of a tablet computer was stated as 65kg.
Critics also cited confusing questions, questions with multiple possible answers and others where knowledge from outside the course would have been necessary, such as the legislation around cloning of phones.
One teacher from a school in Edinburgh said it was “the most error-strewn and, in places, incomprehensible examination I’ve seen in my career” and some questions would have defeated even the most able and best prepared candidates.
Ross Greer, education spokesman for the Scottish Greens, backed the calls for an inquiry as students and teachers had been “badly let down”.
“How a paper which seems so thoroughly flawed could have made it through quality control processes and onto students’ desks raises serious concerns and I will be raising this issue with ministers as soon as possible,” he said.
A spokesman for the SQA said: “The National 5 computing science exam paper met our published course and assessment specifications. The paper did contain a small number of typographical errors.”