Early intervention programmes in the past have made the mistake of concentrating on the first few years of primary literacy, then allowing teachers to lapse into the bad old habits of over-reliance on worksheets and unstimulating activities for older pupils.
The team behind North Lanarkshire's Active Literacy programme is all too aware of such pitfalls and is developing the same kinds of interactive approaches to reading and writing for upper primary that have characterised their work for younger pupils.
After three years, the signs in North Lanarkshire are looking good, with gains across the board, but particularly at the bottom end of the ability spectrum.
If this programme can cut the proportion of P3 pupils who struggle with literacy from 13 per cent to 2 per cent, it has the potential to transform their futures. The high level of illiteracy among youngsters in the "Neet" group (not in education, employment or training) and among prisoners is testament to what can happen to children who drop out of learning because their lack of literacy skills prevents them from keeping up.
If there is one lesson to be learnt from the interventions in North Lanarkshire and West Dunbartonshire literacy programmes, it is this: we need high-quality professional development of teachers, making learning enjoyable, motivating pupils, and using a consistent approach beyond the early years.
These two authorities have adopted different approaches to the teaching of phonics, but if the end result is confident readers and writers, the variations are unimportant.
As the Labour Party's literacy commission embarks on its crusade to find ways of banishing illiteracy from Scotland's shores, its members should beware of too narrow a view. West Dunbartonshire may have scored important successes, but other authorities are delivering results too.