ABSTRACT
Two major problems for a theory of coordinated movement are considered: The context-conditioned variability in the terminal variables of the motor apparatus, and the management of the large number of degrees of freedom that the motor apparatus attains. One approach to these problems argues that, in general, the free-variables of the motor apparatus are not controlled individually, but are partitioned into a smaller number of collectives, where each collective regulates internally and relatively autonomously a number of degrees of freedom. Another and closely related approach seeks to identify a system in which the responsibility for planning and executing an act is optimally distributed across the components of the system. This paper develops the concept of coordinative structure in concert with the first approach. Using the second approach, the paper lays the ground for showing that the perception and action systems participate in a style of organization in which the operational component and the context of constraint are wedded together into a single, relatively closed system. Such a system is referred to as a coalition, and it is claimed that a coalition is the minimum organization required to solve the problems of context-conditioned variability and degrees of freedom.
