SCOTTISH teachers don’t have the mathematical skills to be able to interpret the results of controversial primary school tests, according to an expert.

Lindsay Paterson, professor of educational policy at Edinburgh University, told the Scottish Parliament the issue made the results of P1 assessments “invalid”.

The tests for pupils in P1, P4, P7 and S3 were introduced by First Minister Nicola Sturgeon following concerns over falling standards of literacy and numeracy.

However, critics argue the move is counterproductive and can be upsetting for the youngest pupils.

The latest concerns, which emerged at a meeting of the education committee, centre on the fact pupils in P1 can be at significantly different stages of maturity because ages range from four-and-a-half to six-years-old.

Mr Paterson said: “It is too big a variation at that very young age. You couldn’t draw valid inferences if you just have the test results and no measurement of progress.”

The academic said councils did not have the statistical expertise to be able to use the assessment results in a valid way.

He added: “Sadly, it has to be said, the vast majority of Scottish teachers don’t have it either.

“You can do a primary teaching degree with a National 5 ... that is not enough to understand the complexities of statistical sampling.

“You might think they would get this in their teacher education programme, but they get no more maths than they took with them from school.

“That is not nearly enough and there is not enough expertise to allow the evidence to be interpreted in schools.”

The academic also warned a decision by the Scottish Government’s to abolish a previous survey of standards - called the Scottish Survey of Literacy and Numeracy (SSLN) - made it harder to know whether Scottish schools were closing the attainment gap between rich and poor.

Mr Paterson said: “It is impossible at present to know reliably whether we are actually closing the attainment gap. We cannot know that because we do not collect valid data.”

Keir Bloomer, convener of the Royal Society of Edinburgh’s education committee, said the body had been “puzzled” by the decision.

He said: “We think the idea of a sample survey is not incompatible with universal assessment of the kind that the new assessments provide and we do not see what the rationale for abandoning it was. It would be perfectly possible to run both systems in parallel.

“We have lost quite a lot of that contextual information and of course, it is very valuable in relation to trying to narrow the attainment gap.”

Earlier this year, MSPs voted to halt the tests for primary one children, but the result was not binding on the Government.

Education Secretary John Swinney has pressed ahead with P1 testing, but also announced an independent review of the policy for the youngest pupils.