In almost every industrial enterprise, clerical work of some kind or another is necessary, and a problem of universal interest has developed around the selection of clerks. The time required to “break in” new employees runs from two weeks to two months, according to the nature of the routine, and this process invariably is very expensive. By means of standardized mental tests the whole process may be greatly simplified. In an experiment recently reported tests were given to fifty-two men and women engaged in clerical and near-clerical work. An aggregate number of 440 tests was given. The manager of the department had made a study of these people and had attempted to rate them as to their actual ability. The tests were classified under the head of tests for _technique_ and tests for _intelligence_. By _technique_ is meant the speed and accuracy shown by clerks in sorting tickets and papers, posting and adding columns of figures, indexing and filing, and in other routine clerical operations. The term _intelligence_ is interpreted to designate the facility and success with which a clerk could master new tasks and follow directions about new work assigned from time to time. The clerk’s _technique_ was indicated by steadiness, arithmetic, card sorting, and substitution-of-letters tests. The _intelligence_ tests included a “hard-directions” test and an “abstract-relations” test, similar to those given in the Mentimeter in this volume. When all the tests had been given the results were computed and tabulated so as to bring out the following points: (1) the rank of each individual with reference to all the rest; (2) the relation of each of four groups to each other; (3) the relation between technique and intelligence. The results were then submitted to the office head, who compared them with his records and with his own opinion of the relative merits of the various individuals. This comparison showed a very marked agreement between the testimony of the tests and the rankings of the office manager. The results of these tests so impressed the office manager that he decided to give them to all incoming clerks. One of the first candidates to be examined was a young woman who had recently been interviewed by one of the office heads. The candidate was so unprepossessing in appearance that in spite of signs testifying to her intelligence, the office head was in doubt as to the advisability of hiring her. The psychological tests were applied. When this was done the young woman did remarkably well in every test. She was then hired, and proved herself so ready and capable that it was decided to train her for the work of an office assistant. In six weeks she had mastered the routine of four different kinds of work. This was a striking instance in which the testimony of the tests belied the testimony of observation.