Machine learning and knowledge acquisition from experts have distinct capab
ilities that appear to complement one another. We report a study that demon
strates the integration of these approaches can both improve the accuracy o
f the developed knowledge base and reduce development time. In addition, we
found that users expected the expert systems created through the integrate
d approach to have higher accuracy than those created without machine learn
ing and rated the integrated approach less difficult to use. They also prov
ided favorable evaluations of both the specific integrated software, a syst
em called The Knowledge Factory, and of the general value of machine learni
ng for knowledge acquisition.