Around 2,000 degree and diploma students who sat a statistics exam at the Singapore Expo on May 7 will have to take it again because of a mistake.
The two-hour paper - set by the University of London (UOL) - did not contain the statistical tables needed for answering the questions.
The students from various tertiary institutes here, including the Singapore Institute of Management (SIM), were expected to answer eight questions in all. But with the tables missing, some parts of the questions could not be completed.
The UOL e-mailed the affected students last Friday to apologise and said it would "commence a detailed deliberation of the assessment" for the subject and the impact the missing tables caused before marking.
However, students received another e-mail yesterday informing them of the retest.
Signed off by Mr Timothy Wade, associate director of assessment and awards for the UOL's international programmes, it said the exam had been "declared null and void".
He added that the university had reviewed the situation and found that the first paper was "flawed" and "does not provide a fair test of candidates' abilities and proficiency in this course".
Students can take a retest on either May 28 or June 3 and will not have to pay a separate exam fee.
Those unable to make the two dates will have to take the exam next May, the e-mail said.
Mr Wade added the university is "sorry that the delivery of the examination service has failed on this occasion". He said it will also review its procedures surrounding the production of exam papers, to ensure the error does not recur.
The UOL told The Straits Times yesterday that it was acting "in the best interest of both its students and the integrity of its academic award" in calling for a retest. SIM, where most of the affected students are from, will also render help, such as holding optional revision classes.
The module is compulsory for a number of UOL courses, including banking and finance, and business and management.
UOL programmes are also offered at institutes such as PSB Academy.
Second-year business and management student Ellen Chan, 21, is upset at having to retake the test.
"Now we have to study for the paper again and I've already made holiday plans," said Ms Chan, who will return before the May 28 test. "I don't understand how the tables got left out. Why didn't anyone check the papers?"
But banking and finance student Aizat Guan, 24, said the retest "is another chance... to complete the paper". He added: "I wasn't satisfied after sitting the first exam, as I couldn't complete it without the tables."
In 2007, the UOL erroneously set a sociology exam paper with only six questions instead of eight.