Predicting impact in an Early Years intervention: the design of a tool using qualitative and quantitative approaches

This article focuses on the design and application of an instrument, the Programme Variability Rating Scale (PVRS), to measure the effectiveness of a complex social intervention in the UK. Sure Start aimed to improve outcomes for children aged under four years living in disadvantaged areas on a wide range of health, educational and social indicators. The PVRS was devised for use in the National Evaluation of Sure Start (NESS) to measure programme proficiency. It consisted of 18 dimensions (eg. parental empowerment, user identification, flexibility of service delivery), each with seven levels of proficiency. It was applied to 150 Sure Start local programmes involved in a longitudinal study of the impact of the intervention on a range of child and parental outcomes. Ratings of more or less proficient processes were related, using discriminant‐function analysis, with the impact outcomes from the cross‐sectional study of almost 20,000 children. The 18 dimensions of proficiency of the PVRS made a significant differentiation between the most and least effective programmes.