The field of altmetrics has grown impressively since its inception in 2010 with the Altmetrics Manifesto (Priem, Taraborelli, Groth, & Neylon, 2010). We now have regular altmetric conferences... Show moreThe field of altmetrics has grown impressively since its inception in 2010 with the Altmetrics Manifesto (Priem, Taraborelli, Groth, & Neylon, 2010). We now have regular altmetric conferences where academic and commercial data analysts and providers meet. A number of non-profit and for-profit platforms provide altmetric data and summarize these data in visually appealing presentations. This growth of altmetrics is partly fueled by the problems encountered in both peer review and indicator-based assessments of scientific activities, and also by the easy availability of novel types of digital data on publication and communication behavior of researchers and scholars. In this paper, we review and reflect on the state of the art with respect to these new altmetric data and indicators in the context of the evaluation of scientific and scholarly performance. Show less