At first sight, the new grading system proposed for GCSEs by exam regulator Ofqual is entirely logical.
There has been criticism of grade inflation under the current system for grading GCSEs with the result that too many pupils are gaining top grades to allow employers and sixth-forms to differentiate between different candidates.
Therefore it makes sense to reduce the number of high-flyers who receive the top grade so that it is reserved for those who show truly excellent performance.
The controversy will come over the decision to make grade five a benchmark which compares with top-performing students in high performing countries in the Organisation for Economic Co-operation and Development’s international league tables.
Two points emerge. Firstly, it is based on the last rankings - which will be out of date when the new GCSEs are first awarded in 2017. Unless the benchmark is regularly re-assessed, it could end up being meaningless.
Secondly, it gives the Department for Education an interesting dilemma. Should schools be ranked on the new international benchmark in exam league tables - or should they stick with grade 4, which will be the equivalent of the current C grade.
My instinct is that Education Secretary Michael Gove will go for grade five for ranking schools - simply because he is anxious to ratchet up standards as much as possible.
Finally, Ofqual needs to make a persuasive case for its new national reference test - otherwise it will faced objections from teachers who will consider it to be a test too many in an already crowded timetable.