As testing becomes more prevalent as a policy tool in the Anglo-Saxon world, debates continue as to whether it supports central reforms of instruction or leads to a kind of 'teaching to the test' that invalidates results and undermines more challenging instruction. This paper reports on a three-year study of mathematics testing of nine-year-olds in New Jersey. Using a mix of surveys and direct observations with interviews, we conclude that New Jersey's testing policies contributed to both results. Where teachers feel more pressure, they respond with short-term test preparation and focus on more didactic instructional strategies. When they know more about state and national standards and have the opportunity to learn more, they are inclined to use more inquiry-oriented approaches and integrate test preparation with regular instruction.