The same tests were given to the twenty-one girls engaged in gauging the head-thickness of shells. This work does not require the use of the eyes. The operator simply picks up a handful of shells and, with or without looking, tries the head of each shell on a gauge. The gauge is a piece of steel with two notches or openings. The shells which are too small pass through the first opening and fall into a box of rejects below. Those that do not fall through are tried on the second opening and, if they pass through, they are of the right size. If they fail to pass through they are too large and are thrown aside. The operator sits in front of her gauge and tries each shell at one opening and then another, just as rapidly as she can move her hands up and down. The tests showed, in this instance, an entirely different set of correlations. The comparative correlation scores follow: ════════════════════════════════╤══════════ TESTS INSPECTORS│ GAUGERS ────────────────────────────────┼────────── Card Sorting .55│ .05 Tapping .14│ .52 Cancellation .63│ .17 General Intelligence .14│ .18 Number Group Checking .72│ —.19 ────────────────────────────────┴────────── Perfect agreement between average daily work and score in the test would be indicated by a correlation score of 1.00, while lack of relationship would be indicated by a correlation of 0 or nearly 0. The score of the gaugers in the tapping test (.52) showed that they were speedier and had greater endurance. This seems reasonable since, in the operation of gauging, speed of movement and endurance are the chief factors. In the visual discrimination tests, such as card sorting, cancellation, and number group checking, the scores of the inspectors were higher. This quality, however, was not necessary to successful operation in gauging. In other operations the results of these tests proved their value as a factor in eliminating blunders in the employment office. Girls who seemed, from observation, to possess the very qualities necessary for one or another operation, frequently puzzled their superiors by their failure to perform some highly important operation of their work. The eight tests would have demonstrated this particular inability and would have saved thousands of dollars lost through delay and mistakes. Similar results were obtained in experiments with men workers.