The GODAN Action project examined the current state of the art of impact evaluation in the field of open data, developed an impact evaluation framework accounting for the specifics of open data use in developing countries, and performed a mix of desktop research and empirical work on case studies to test and underpin its research. This document describes the outcomes of these case studies, examining the potential of open data through the analysis of impact narratives in three thematic topics: weather data, land data and nutrition data. Three use cases per thematic topic have been selected that best illustrated the contexts, impact mechanisms, main actors and barriers towards the achievement of impact. Each thematic topic describes their use cases following a different structure adapted to the specifics of the domain. All cases, however, show the pathways to impact within the different topics and contexts of study, and specific Theories of Change have been developed for each of them. For the weather data case studies, the focus was on the important role of information and service intermediaries as key value chain partner to achieve impact. These case studies are: NOAA Open weather data (United States), a portal that provides weather data information and forecasts including yield predictions; the CommonSense project, which provides Ethiopian farmers with weather forecasts and farm management advice (e.g. based on earth observations and geographic data), to help them make more informed decisions on farming activities; and the GEOBIS project, which provides farmers in Bangladesh with weather related information and advice on farm management (usage of seeds, sowing, irrigation, fertilizers, among others). Land data impact narratives are described according to the different data aggregator levels: local, regional and global. On the global level and working towards a more inclusive data ecosystem, it analyses the work between Land Portal (a free online platform working towards a more accessible land governance information landscape) and Land Conflict Watch (a research-based data journalism project in India). At a regional level and related to the ‘enabling’ factor of data ecosystems, the impact narrative focuses on the Open Development Mekong, an open knowledge platform that advocates for transparency and promotes debate over basic data. Data mapping is described at a grassroots level through the example of NRMC, an advisory firm in India that attempts to bridge information gaps, create evidence-based advocacy and build platforms for connection among land stakeholders. Open nutrition data impact pathways have been assessed by examining the work of an open data intermediary, the Global Nutrition Report (GNR) and its relevance for national and regional policy actors. The GNR is a flagship publication which weaves together (open) data from a variety of sources to create a snapshot of the state of nutrition worldwide and capture progress towards the SDGs. The examination of GNR’s work highlights some additional opportunities and challenges of placing open data at the heart of sense-making and action. The cases of two national/regional initiatives, the Tanzanian Food and Nutrition Centre (TFNC) and the New Partnership for Africa’s Development (NEPAD) illustrate how such initiatives use data of global aggregators in the work they undertake.