It would appear from some of the preliminary results of network simulations that it may be useful to have elements become “fatigued” after undergoing an excessive number of weight changes. Experiments have been performed on simplifications of the model described so far which had the occasional result that a small number of elements came to a state where they received most of the weight increments, much to the detriment of the learning process. In such cases the network behaves as if it were composed of many fewer adjustable elements. In a sense this is asking each element to maintain a record of the data it is being asked to store so that it does not attempt to exceed its own information capacity. It is not certain just how this fatigue factor should enter in the element’s actions, but if it is to be compatible with the variable bias method, this fatigue factor must enter into the element’s response to a changing bias. Once an element changes state with zero sum at the same time that the final output becomes wrong, incrementing must occur if the method is to work. Hence a “fatigued” element must respond less energetically to a change of bias, perhaps with a kind of variable factor to be multiplied by the bias term. NETWORK STRUCTURE It is felt that the problem of selecting the structure of interconnections for a network is intimately connected to the previously mentioned problem of generalization. Presumably a given type of generalization can be obtained by providing appropriate fixed portions of the network and an appropriate interconnection structure for the variable portion. However, for very large networks, it is undoubtedly necessary to restrict the complexity so that it can be specified by relatively simple rules. Since very little is known about this quite important problem, no further discussion will be attempted here. COMPUTER SIMULATION RESULTS A computer simulation of some of the network features previously described has been made on an IBM 7090. Networks with an excess of elements and with only positive interconnecting weights were used. However, in place of the variable bias method, a simple choice of the element of sum closest to, and on the wrong side of, zero was made without regard to the effectiveness of the element in correcting the final output. No fatigue factors were used. The results of these simulations are very encouraging, but at the same time indicate the need for the more sophisticated methods. No attempt will be made here to describe the results completely.