In partnership with Southern Voice, this research project aimed to develop a methodological framework for assessing development effectiveness and to rebuild this discourse from the ground up, informed by Southern perspectives. The key objective of the study was to create a methodological guide that utilized new sources of data and techniques for assessing development effectiveness. The study provided an overview of possible sources of new and innovative data (primarily open access and public data) with reference to some case studies in the context of assessing development effectiveness. It  undertook a comparative review of scope for innovative data and techniques (including geospatial and Big Data) for assessing development effectiveness in developing countries; highlighted the advantages and disadvantages (limitations) of the available techniques and data, and discussed associated challenges and debates (including privacy issues). The study proposed a set of alternative methodologies applicable at the country level for measuring development effectiveness using innovative data and techniques, and it related the proposed methodology to inputs, processes, and outputs.