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techniques for prediction and control; for artificial systems, it must provide practical algorithms and strategies. Theory should help us to know more of the mechanisms of adaptation and of the conditions under which new adaptations arise. It should enable us to better understand the processes whereby an initially unorganized system acquires increasing self-control in complex environments. It should suggest procedures whereby actions acquired in one set of circumstances can be transferred to new circumstances. In short, theory should provide us with means of prediction and control not directly suggested by compilations of data or simple tinkering. The development here will be guided accordingly. |
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The fundamental questions listed above can serve as a starting point for a unified theory of adaptation, but the informal phrasing is a source of difficulty. With the given phrasing it is difficult to conceive of answers which would apply unambiguously to the full range of problems. Our first task, then, is to rephrase questions in a way which avoids ambiguity and encourages generality. We can avoid ambiguity by giving precise definitions to the terms appearing in the questions, and we can assure the desired generality if the terms are defined by embedding them in a common formal framework. Working within such a framework we can proceed with theoretical constructions which are of real help in answering the questions. This, in broad outline, is the approach we will take. |
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(Since we are operating outside of a formal framework in this chapter, some of the statements which follow will be susceptible of different, possibly conflicting interpretations. Precise versions will be formulated later.) |
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Just what are adaptation's salient features? We can see at once that adaptation, whatever its context, involves a progressive modification of some structure or structures. These structures constitute the grist of the adaptive process, being largely determined by the field of study. Careful observation of successive structural modifications generally reveals a basic set of structural modifiers or operators; repeated action of these operators yields the observed modification sequences. Table 1 presents a list of some typical structures along with the associated operators for several fields of interest. |
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A system undergoing adaptation is largely characterized by the mixture of operators acting on the structures at each stage. The set of factors controlling this changing mixturethe adaptive planconstitutes the works of the system as far as its adaptive character is concerned. The adaptive plan determines just what structures arise in response to the environment, and the set of structures attainable |
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