22 II A FIRST EXPERIMENT The general purpose of this experiment was to discover a set of mental tests which could be used by the employ ment office in selecting applicants for certain kinds of work. Just where and how, specifically, this was to be done was a somewhat hazy problem at the outset. Hith erto, the work of the experimenter had been confined to the orthodox experiments of the psychological laboratory. Factory conditions and factory problems were therefore novel to him, no more, however, than his purposes and methods were to the factory. In the midst of this some what hazy and intricate problem, four distinct conditions were discernible. First, in finding the proposed set of tests, it was primarily necessary to go out among the shops and make a general survey of the types of work for which applicants were being chosen. Secondly, it was necessary to make an intensive study of one or two op erations at the start, rather than an extensive study of a large variety of operations. Thirdly, a large number of workers all engaged in the same work had to be studied in order to make as wide a series of observations as possible (obviously, the tests tried on a hundred workers would give more conclusive results than those tried on only ten or twenty). Fourthly, it was advisable to try out these tests where the work was simplest and most automatic, on the assumption that the more standardized the work the more easy it would be to dis cover a standard set of tests.