In all sciences, the experimenter is constantly seeking to improve both the accuracy of his observations and the speed with which they can be obtained. He wishes, further, to use the minimum of basic equipment, and to obtain the maximum simplicity in collecting his results. Unfortunately, these factors frequently act in opposite senses: an expensive apparatus, for example, may be required to collect accurate data quickly. In certain fields, it is even worth while deliberately to sacrifice accuracy in order to gain advantage both in speed and simplicity. Thus, in astronomical navigation, it may be possible to simplify sight reduction, to cut down on the bulk of tables carried in the air, and to reduce the time taken for observation and reduction of a sight. The penalty will be a loss in accuracy, but, provided this is not reduced beyond a certain level, it may well be worth while. A review of the requirements for air navigation, and an examination of the problems of position finding by the stars against these requirements may lead to some conclusions as to whether an advantage is to be obtained by simplifying the methods.