The senior chief inspector of schools told directors of education last week that setting was "an important part of the overall armoury but not in itself a panacea".
Graham Donaldson said: "The language we use is critical. When we talk about top and bottom sets, we reveal a view of ability which may well lead to inappropriate expectations. The purpose of setting is to allow pupils'
needs to be addressed more effectively. The key lies in prior learning and not in general ability."