  Major European Union-funded research infrastructure and open science projects
have traditionally included dissemination work, for mostly one-way
communication of the research activities. Here we present and review our
radical re-envisioning of this work, by directly engaging citizen science
volunteers into the research. We summarise the citizen science in the
Horizon-funded projects ASTERICS (Astronomy ESFRI and Research Infrastructure
Clusters) and ESCAPE (European Science Cluster of Astronomy and Particle
Physics ESFRI Research Infrastructures), engaging hundreds of thousands of
volunteers in providing millions of data mining classifications. Not only does
this have enormously more scientific and societal impact than conventional
dissemination, but it facilitates the direct research involvement of what is
often arguably the most neglected stakeholder group in Horizon projects, the
science-inclined public. We conclude with recommendations and opportunities for
deploying crowdsourced data mining in the physical sciences, noting that the
primary goal is always the fundamental research question; if public engagement
is the primary goal to optimise, then other, more targeted approaches may be
more effective.
