The majority of the investigation and analysis for the RETHINK big Project is performed in well-focused, well-prepared surveys and meetings in which Working Groups play the central role. The Working Groups are composed of 2 tiers of participation. Tier 1 comprises the Project Partners which includes some of the major players in hardware, networking and software support in addition to European Big Data practitioners. The Partners will be directly responsible for the acquiring, discussing and synthesizing input from key industrial and academic players or stakeholders from Tier 2 into the interim deliverables and ultimately, the roadmap. Tier 2 is comprised of the representatives of the stakeholders in the outcome of the project; these are Big Data practitioners and technology providers who will directly benefit from a clear roadmap for advancements in technology support for Big Data in Europe.