This paper presents the methodological process and results of the OECD 2017 Open-Useful-Reusable Government data Index (OURdata Index). It is meant to present the methodology and outline the data collection and verification process; discuss key findings of the composite indicators including overall country scores and scores by pillars and sub-pillars; and show the outcomes of different statistical tests to assess the robustness of the results, including tests to evaluate the sensitivity of the indicators to various weighting schemes. The paper highlights the relevance of the Index to support the design and monitoring of open government data policies and practices leading to socio-economic outcomes and to the improved performance and efficiency of public sector organisations.