CASE STUDY research was conducted to elucidate how the oftcited observ
ation that assessment drives instruction plays out for particular indi
viduals within particular schools. Because the influence of assessment
on instruction might be subtle, e.g., textbook selection discussions
might be influenced by the content of particular tests, the work was s
ituated within the decision-making structure of the school and distric
t. Findings suggest that the relationship between assessment and instr
uction is more complex than the debate about whether one does or shoul
d drive the other. Rather, issues of assessment and instruction are em
bedded within broader power structures within our schools; both are in
fluenced greatly by the decision-making model operating in a given dis
trict. Only assessment-as-test proved to drive instruction and then on
ly in districts in which teachers held little curricular authority. Sh
ould this finding hold across other sites in other settings, it sugges
ts that two current reform efforts-better rests and greater reliance o
n school-based management-may be incompatible.