  Empirical studies form an integral part of visualization research. Not only
can they facilitate the evaluation of various designs, techniques, systems, and
practices in visualization, but they can also enable the discovery of the
causalities explaining why and how visualization works. This state-of-the-art
report focuses on controlled and semi-controlled empirical studies conducted in
laboratories and crowd-sourcing environments. In particular, the survey
provides a taxonomic analysis of over 129 empirical studies in the
visualization literature. It juxtaposes these studies with topic developments
between 1978 and 2017 in psychology, where controlled empirical studies have
played a predominant role in research. To help appreciate this broad context,
the paper provides two case studies in detail, where specific
visualization-related topics were examined in the discipline of psychology as
well as the field of visualization. Following a brief discussion on some latest
developments in psychology, it outlines challenges and opportunities in making
new discoveries about visualization through empirical studies.
