Building on two decades of national surveys in the United States and t
wo Eurobarometer studies, the history, rationale, and structure of a m
easure of civic scientific literacy are described. Estimates of the pr
oportion of adults who are very well informed or moderately well infor
med on the index of civic scientific literacy appear in the literature
more frequently, and this paper provides the first comprehensive desc
ription and analysis of the civic scientific literacy measure. It is h
oped that this analysis and discussion will encourage the inclusion an
d replication of the measure in a wider range of studies of the public
understanding of and attitudes toward science and technology.