This paper describes the design and development of a set of teaching m
aterials for the teaching of a topic on mechanics (as part of the rese
arch carried out for the 'Conceptual Change in Science' project). The
'curriculum' comprises a series of interactive computer simulations of
force and motion, a number of closely related practical activities an
d associated written materials. The aim of the materials was to promot
e change in learners' understandings of physical phenomena, by first m
aking them aware of the limitations of their current conceptions, and
then by enabling learners to develop and use a conceptual framework wh
ich both fits with their experience and is internally consistent.