Equally worrisome is that today's assessments emphasize narrow skill sets such as geometry and grammar, and omit huge chunks of what educators and business leaders say is essential for modern students to learn: creative thinking, problem solving, cooperative teamwork, technological literacy, and self-direction. Yet because NCLB has made accountability tests the tail that wags the dog of the whole education system -- threatening remediation and state takeover for schools that fall short -- what's not tested often isn't taught.

many experts tout the Programme for International Student Assessment (PISA) exam for its challenging, open-ended questions on practical topics, such as climate change or the pros and cons of graffiti. Even more advanced models, some using computer simulations, will become available in a few years -- and none too soon.

static problem, for instance, would ask test takers to say from memory how to save a certain endangered bird species. A dynamic assessment (in a real example from Bransford's lab) asks students to use available resources to learn what it would take to prevent the white-eyed vireo from becoming endangered. This is a novel question that demands students independently dig for information and know enough to ask the right questions to reach a solution.