Another computer glitch has hit primary schools in Northern Ireland.
Although the results of tests received by pupils and parents were correct, standardised literacy scores used by schools to plot their progress were wrong, the body which overseas assessment said.
The computer-based tests were carried out on pupils in p4-p7 at the start of the year.
A Council for the Curriculum, Examinations and Assessment (CCEA) statement said: "We are extremely disappointed that an error was introduced into the calculation of the scores and we apologise for any distress or inconvenience caused.
"It is particularly frustrating as the scores presented to us for review in January were correct. An error was subsequently introduced into the data by our literacy assessment provider prior to the information being made available to schools via the company's website in February."
The outcomes of the assessments are used to identify areas of strength and areas for improvement for each pupil to help inform teaching and learning throughout the remainder of the school year.
The CCEA said the results received by parents and pupils were correct. All numeracy results were right, the problem was with standardised scores for literacy.
The error was found in standardised scores for the assessment provided by Tribal Group. Age-related results, those reported to parents, were not affected.
The error has been fixed and the correct standardised data is now available.
Last October up to 400 primaries had problems with computer assessments.