For most people, prism adaptation is an amusing demonstration, first experienced perhaps in an introductory psychology course. This monograph relates this peculiar phenomenon to the larger context of cognitive science, especially motor control and learning. The first part sketches the background concepts necessary to understand the contribution of prism adaptation to the larger issue of adaptive perceptual-motor performance including: * a review of the basic concepts of motor control and learning that enable strategic response in the prism adaptation situation; * the development of a hypothesis about spatial representation and spatial mapping and an introduction to the basic idea of adaptive spatial alignment; and * a contrasting view of perceptual and motor learning and a review of evidence for the involvement of nonassociative and associative learning in prism adaptation. Directly concerned with data and theory in prism adaptation, the second part presents: * an outline of prism adaptation methodology and a list of several empirical conclusions from previous research that constrained development of theoretical framework; * a theory of strategic perceptual-motor control and learning which enables adaptive performance during prism exposure, but does not directly involve adaptive spatial alignment; * an extention of the theory to include realignment processes which correct for the spatial misalignment among sensorimotor systems produced by prisms; and * a demonstration of how traditional issues in prism adaptation may be rephrased in terms of the present theoretical framework. The last part of this volume reviews the research conducted in developing and testing the present theory of prism adaptation. It summarizes the initial investigations (employing a naturalistic exposure setting), reports some more rigorous tests with an experimentally constrained research paradigm, points out the more general theoretical issues raised by the authors' analysis of prism adaptation, and makes specific suggestions for further research within the prism adaptation paradigm.