The main objective of the *metrics – MEasuring The Reliability and perceptions of Indicators for interactions with sCientific productS project is to develop a deeper understanding of *metrics (aka altmetrics / social media metrics), in terms of their general significance and their perception amongst stakeholders. Key considerations will include the quality of *metrics’ underlying data (in terms of validity and reliability), the historical context within which *metrics arose, as well as their ability to adequately assess scientific outputs against the background of disciplinary specificities. The project’s findings will benefit *metrics users and will contribute to the greater openness and transparency of *metrics initiatives.