5 8 EMPLOYMENT PSYCHOLOGY Heretofore tests had first been tried in the shops where a comparison with the actual production of those to whom they were given made it possible to get an immediate index of their value. In this case it was impossible to do this, because, as has already been stated, the force intended to do this work had not yet been built up. Therefore, tests having been chosen as well as possible under the circumstances, they were given immediately to new girls as they came into the employment office in search of work. The girls chosen on the basis of these tests were carefully watched, and after a period of from one to two months from the time at which they had been chosen, an attempt was made to compare their performance in the tests with their ability as assemblers. However, because each girl was assembling slightly different parts it was impossible to rank their ability on the basis of production records. Consequently, the opinions of the foreman and section head were sought. It may be said here that personal opinions of this kind are a very poor substitute under any circumstances for the impersonal testimony expressed by cold production figures. However, the girls concerned had been watched with particular care, since this was also an experiment on the part of the shop in introducing women for this kind of work. The rankings of the fore man and section boss were obtained independently of each other and agreed in every case but one. The records of the girls in the tests were then compared with these rankings, and a remarkable agreement was found. Eighteen girls had been tested. Of this number twelve had been hired for assembling work. Ten of the twelve were still there. The two who had left were girls who had done poor work in the tests. Those girls who had done