Reading and writing difficulties are markers for some forms of learning disorders, and measuring the distance between the child's performance and an expected level of attainment is a common approach to diagnosis. However, there are several problems with relying on the gap between achievement and expectation for arriving at a diagnosis, not least because the approach is essentially blind to the child's history of opportunity. An alternative approach offers children tiers of individualised programmes, and their changing strengths and weaknesses informs the diagnosis. This article reports the findings of an exploratory study analysing the change scores of ten children who were reading two years behind their class level. We offered a two-tiered language intervention, embedded within a whole class programme, using the children's narrative writing for examining change. Our findings suggest that the profile of strengths and weaknesses gathered from a school-based intervention is a valuable complement to a clinical assessment.