One of Scotland's foremost education academics has described today's figures on Scotland's standing in the world as "shocking".
Lindsay Paterson, Professor of Education Policy at Edinburgh University, says Scotland has gone from being at or above England to below its southern neighbour.
In analysis provided to ITV Border Prof Paterson says:
The PISA (Programme for International Student Assessment) tests look at the performance of 15-year-olds in a range of countries in the three "domains" of science, reading and mathematics.
Prof Paterson highlights what he believes could be one of the causes of this decline - Scotland's 'Curriculum for Excellence' (CfE) the philosophy which underlies all school teaching north of the Border.
In an analysis which will be widely read, Prof Paterson asks: "What has changed that might explain this dismaying Scottish performance?"