Computer-based literacy and numeracy tests used by schools in Northern Ireland which developed a series of technical glitches have cost almost £3 million, it was revealed.
Numerous faults were reported by teachers trying to run the software.
Some results of literacy assessments from thousands of pupils used by schools to see how they compared to other schools and other areas were wrong, it emerged recently.
DUP MLA Mervyn Storey said: "If the minister (John O'Dowd) had listened to the common sense of the teachers in the schools he would have had no need to sign a contract to give out public money to do tests which are not worth the paper they are written on. He should have used the tests teachers currently use which are working, accepted by the inspectorate and a lot cheaper to the schools."
The problem concerned tests taken by 88,000 pupils in P4 and P7 across Northern Ireland last autumn. The Council for the Curriculum, Examinations and Assessment (CCEA) said literacy and numeracy results received by pupils and parents were correct. The problem was with standardised scores for literacy, used to measure overall school performance.
Education Minister Mr O'Dowd has ordered an investigation and said failings in the tests were unacceptable. He told Mr Storey £1.2 million had been paid to two commercial companies involved in supplying the assessments.
When teacher and administrative staff time, venue hire and printing are added on, the cost comes to £2.8 million from November 2011 to last March, the minister said. He has announced that the computer-based assessments will no longer be compulsory for schools following complaints from teachers.
He added recently: "However I know that schools value diagnostic assessment early in the year and plan to conduct assessments voluntarily using a range of tools. Consequently, I expect diagnostic assessment will take place, in a form that is convenient for schools, and that this information will feed into engagement with parents."
The minister went on to say that the numeracy and literacy tests will still be available to those schools who wish to avail of them. He said: "The NINA (numeracy) and NILA (literacy) assessments remain unique: they are designed to reflect our curriculum and are standardised against our pupils. I accept that there were major issues last year but it would be a real shame and missed opportunity if these bad experiences lead us to lose this potential.
"I believe there is continued benefit for schools in using these bespoke assessments and for this reason NILA and NINA will be available to schools on a voluntary basis."