In partnership with Southern Voice, this research project aimed to develop a methodological framework for assessing development effectiveness and rebuild this discourse from the ground up, informed by Southern perspectives. The key objective of the study was to develop a methodological guide that makes use of new sources of data and techniques in 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; 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 associated challenges and debates (including the issue of privacy); proposed a methodology (or a set of alternative methodologies) which may be applied at the country-level for measuring development effectiveness using innovative data and techniques; related the proposed methodology with inputs (instruments), processes and outputs (outcomes).