Project IMPACT is a school-based teacher enhancement model for element
ary mathematics instruction designed to foster student understanding a
nd to support teacher change in predominantly minority elementary scho
ols. Project teachers consider instructional approaches consistent wit
h a cognitive, constructivist perspective for mathematics learning, em
phasizing interaction and collaboration rather than limiting instructi
on to a direct model. Data from the primary grades revealed that signi
ficantly higher mathematics achievement scores for the children in the
IMPACT schools emerged gradually and persistently over time, becoming
more evident as the mathematical abstraction of the curriculum increa
sed. Supported by mathematics specialists, instructional change occurr
ed in most treatment classrooms, particularly in those schools where t
he principal encouraged the reform.