learning attempts, and regulating the complexity and difficulty of levels of information for them.

Neurocognitive research has contributed evidence that both the developing and the mature brain are structurally altered during learning. For example, the weight and thickness of the cerebral cortex of rats is altered when they have direct contact with a stimulating physical environment and an interactive social group. The structure of the nerve cells themselves is correspondingly altered: under some conditions, both the cells that provide support to the neurons and the capillaries that supply blood to the nerve cells may be altered as well. Learning specific tasks appears to alter the specific regions of the brain appropriate to the task. In humans, for example, brain reorganization has been demonstrated in the language functions of deaf individuals, in rehabilitated stroke patients, and in the visual cortex of people who are blind from birth. These findings suggest that the brain is a dynamic organ, shaped to a great extent by experience and by what a living being does.

A major goal of schooling is to prepare students for flexible adaptation to new problems and settings. Students’ abilities to transfer what they have learned to new situations provides an important index of adaptive, flexible learning; seeing how well they do this can help educators evaluate and improve their instruction. Many approaches to instruction look equivalent when the only measure of learning is memory for facts that were specifically presented. Instructional differences become more apparent when evaluated from the perspective of how well the learning transfers to new problems and settings. Transfer can be explored at a variety of levels, including transfer from one set of concepts to another, one school subject to another, one year of school to another, and across school and everyday, nonschool activities.

People’s abilitiy to transfer what they have learned depends upon a number of factors:

• People must achieve a threshold of initial learning that is sufficient to support transfer. This obvious point is often overlooked and can lead to erroneous conclusions about the effectiveness of various instructional approaches. It takes time to learn complex subject matter, and assessments of transfer must take into account the degree to which original learning with understanding was accomplished.

• Spending a lot of time (“time on task”) in and of itself is not sufficient to ensure effective learning. Practice and getting familiar with subject matter take time, but most important is how people use their time while