Davis said the students didn't complain that the exam was too hard and the mistake was only picked up when the completed exams were being collected to forward to the Qualifications Authority (NZQA).
The college alerted NZQA about the mistake on October 21 and had asked for advice on what to do.
"The students were worried that they would have to sit it again, and they were worried that their grades would be lower than they should be," Davis said.
He said some students might have passed the exam even though it was at a higher level than they expected, and the college suggested that they could have been given Level 3 credits for it.
However NZQA ruled that this was not possible because the students had not been taught the Level 3 material, so it decided to invoke an "unexpected event grade" process in which students have been given Level 2 credits derived from their previous work.
The DigiCAT, a part of Digital Technologies that schools can choose to enter, is worth three credits towards Level 2 of the National Certificate of Educational Achievement (NCEA), which requires a total of at least 60 Level 2 credits plus at least 20 at Level 1 or above.
The mistake has come to light just before 140,000 students nationally begin the main NCEA exams on Monday, November 16. The exams are 10 days later than usual because of this year's Covid-19 lockdowns.
NZQA has been blamed for a series of mistakes in NCEA exams in recent years, but in this case the mistake was made by the college.
Davis said no one would be disciplined as a result.
"Our IT manager is meticulous in his work. He is beating himself up about this. He just feels absolutely terrible that it happened," Davis said.
"It's one of those trust things. Richard has done this [managed digital exams] so long, we trust that he has done it right. No one thought that it wouldn't be the Level 2 exam that was asked for.
"I would be confident in saying that it would never happen again, because it happened once."
NZQA deputy chief executive Kristine Kilkelly said the DigiCAT was set by NZQA but schools marked it themselves.
"Western Springs College carried out an investigation and reported the outcome to NZQA. They also identified changes they can make, and this helped NZQA to identify possible improvements," she said.
"NZQA will work with Western Springs College to develop processes that can be carried forward to support schools and to minimise the chance of a similar incident happening in future.
"No students noticed that the wrong standard had been loaded and they all made a genuine attempt to answer the higher-level paper.
"The school has supplied grades for the affected students based on pre-existing standard specific evidence. This evidence does not have to be a practice examination; NZQA has supplied templates for schools to use to gather evidence in this Covid-affected year.
"It is worth noting this examining platform is different from that used in NCEA external examinations – tasks are not loaded onto a computer but are cloud based and personalised to each student."
