Three-quarters of parents and carers have not heard of the new accountability measure Progress 8, according to a new survey.
And of those who have heard of Progress 8, less than a fifth (19 per cent) of parents and carers understand how it works, a poll finds.
In January this year, all schools were ranked on the government's new performance measure in the key stage 4 performance tables.
Progress 8 – which was used for the first time this year – replaced the previous measure of five A* to C GCSE grades, including English and maths.
But a survey of more than 1,500 parents and carers of secondary school children has revealed that only 19 per cent have heard of Progress 8.
And there is still confusion about the GCSE grading reforms, which come into effect this summer for maths and English. A fifth of parents and carers have not heard of the new numerical 9 to 1 scale which will replace A* to G.