  Advances in science are being sought in newly available opportunities to
collect massive quantities of data about complex systems. While key advances
are being made in detailed mapping of systems, how to relate this data to
solving many of the challenges facing humanity is unclear. The questions we
often wish to address require identifying the impact of interventions on the
system and that impact is not apparent in the detailed data that is available.
Here we review key concepts and motivate a general framework for building
larger scale views of complex systems and for characterizing the importance of
information in physical, biological and social systems. We provide examples of
its application to evolutionary biology with relevance to ecology,
biodiversity, pandemics, and human lifespan, and in the context of social
systems with relevance to ethnic violence, global food prices, and stock market
panic. Framing scientific inquiry as an effort to determine what is important
and unimportant is a means for advancing our understanding and addressing many
practical concerns, such as economic development or treating disease.
