DANS is an institute of the Royal Netherlands Academy of Arts and Sciences (KNAW) and the Netherlands Organization for Scientific Research (NWO) that focuses on digital archiving and long-term accessibility of research data. The presentation discusses the development of metrics to measure science over time, including bibliometrics, altmetrics, and new types of metrics for research assessment. It argues that metrics should be tailored to their purpose and granularity of analysis, and that qualitative research should complement quantitative metrics. New research information systems and ontologies can help understand science dynamics if they clearly communicate their scope and limitations.