  This Journal of Informetrics special issue aims to improve our understanding
of the structure and dynamics of science by reviewing and advancing existing
conceptualizations and models of scholarly activity. Several of these
conceptualizations and models have visual manifestations supporting the
combination and comparison of theories and approaches developed in different
disciplines of science. Subsequently, we discuss challenges towards a
theoretically grounded and practically useful science of science and provide a
brief chronological review of relevant work. Then, we exemplarily present three
conceptualizations of science that attempt to provide frameworks for the
comparison and combination of existing approaches, theories, laws, and
measurements. Finally, we discuss the contributions of and interlinkages among
the eight papers included in this issue. Each paper makes a unique contribution
towards conceptualizations and models of science and roots this contribution in
a review and comparison with existing work.
