  We present a novel approach to visually locate bodies of research within the
sciences, both at each moment of time and dynamically. This article describes
how this approach fits with other efforts to locally and globally map
scientific outputs. We then show how these science overlay maps help benchmark,
explore collaborations, and track temporal changes, using examples of
universities, corporations, funding agencies, and research topics. We address
conditions of application, with their advantages, downsides and limitations.
Overlay maps especially help investigate the increasing number of scientific
developments and organisations that do not fit within traditional disciplinary
categories. We make these tools accessible to help researchers explore the
ongoing socio-cognitive transformation of science and technology systems.
