The gap in performance between this year's Standard grade maths and English exams have prompted calls to the Scottish Qualifications Authority to ensure the design of the new National 4 and 5 qualifications is more flexible.
Fewer than 1,800 pupils received Foundation awards in English compared with more than 10,000 in maths - an outcome blamed on the inflexible structure of the maths courses.
Gill Stewart, SQA director of qualifications, told TESS there would be more flexibility in the new system than there is currently. The units in the new National 4 and 5 qualifications leading to Highers were designed to be hierarchical, she said.
Analysis of the two highest uptake subjects showed that more than half of pupils who sat the English Standard grade exam achieved Grade 3 or 4 passes (General level) compared with a third in maths.
In maths, about a quarter gained Grade 5 and 6 passes (Foundation), while in English, it was about 3 per cent.
Larry Flanagan, education convener of the EIS union, believes the differences in performance can be explained by the lack of flexibility in maths to move between the Foundation, General and Credit levels.
"In English, the fundamental course remains the same. But the setting that takes place in maths revolves around different courses, so Foundation is different from General and Credit courses."
Mr Flanagan, who is a principal teacher of English, said that most of his pupils currently would sit Credit and General papers, or General and Foundation in Standard grade English.
But he fears that the new National 4 and 5 qualifications will not offer the same bi-level presentation options.
Janet Brown, SQA chief executive, said the point of Curriculum for Excellence was to get away from over-assessment. "Why are we putting pupils in for two levels of exam? If the system understands the standard of the examination and what people should be attaining at a particular level, it is better for the candidate if they only take one level," she said.