Educational partnerships with area-based approaches comprise an increasingly well-grounded and internationally extended strategy for equitable improvement. However, literature shows a lack of focused inquiry on the assessment of these educational collaborative programmes. This article aims to develop and validate an instrument to assess these types of programmes across countries. Two successful programmes were assessed in Spain and the USA in order to test the validity of the measurement model. Results confirm that the model provides a valid tool to assess the effectiveness of collaborative performance, helping school principals, district leaders and policy-makers to enact evidence-based decision-making.