This report updates a 1983 analysis of fifty-eight knowledge gap studi
es, adding thirty-nine studies and pointing out innovative ways to imp
rove research in the area. The persistence of knowledge inequalities a
cross topics and research settings has serious consequences. Gaps in p
ublic affairs and health knowledge have an especially severe impact on
those groups most negatively affected by socioeconomic changes, who a
lso tend to be information poor. Rapid growth of socioeconomic divisio
ns between ''haves'' and ''have-nots'' in the last two decades suggest
s that knowledge gaps deserve increased research attention because the
y are related and potentially affected phenomena.