(4) In forming organizations of superior mental strength where such superiority is demanded by the nature of the work to be performed; (5) In selecting suitable men for various army duties or for special training in colleges or technical schools; (6) In the early formation of training groups within a company in order that each man may receive instruction and drill according to his ability to profit thereby; (7) In the early recognition of slow-thinking minds which might otherwise be mistaken for stubborn or disobedient characters; (8) In eliminating from the army those men whose low-grade intelligence renders them either a burden or a menace to the service. _Nature of the Tests._—The tests were prepared by a special committee of the American Psychological Association. Before being ordered into general use they were thoroughly tried out in four National Army Cantonments, and from time to time have undergone revision to increase their practical usefulness. Between May 1 and October 1, 1918, approximately one million three hundred thousand men were tested. Three systems of test are now in use:— (1) _Alpha._ This is a group test for men who read and write English. It requires only fifty minutes, and can be given to groups as large as 500. The test material is so arranged that each of its 212 questions may be answered without writing, merely by underlining, crossing out, or checking. The papers are later scored by means of stencils, so that nothing is left to the personal judgment of those who do the scoring. The mental rating which results is therefore wholly objective. (2) _Beta._ This is a group test for foreigners and illiterates. It may be given to groups of from 75 to 300 and requires approximately fifty minutes. Success in Beta does not depend upon knowledge of English, as the instructions are given entirely by pantomime and demonstration. Like Alpha, it measures general intelligence, but does so through the use of concrete or picture material instead of by the use of printed language. It is also scored by stencils and yields an objective rating. (3) _Individual Tests._ Three forms of individual tests are used: The Yerkes-Bridges Point Scale, the Stanford-Binet Scale, and the Performance Scale. An individual test requires from fifteen to thirty minutes. The instructions for the Performance Scale are given by means of gestures and demonstration, and a high score may be earned in it by an intelligent recruit who does not know a word of English. All enlisted men are given either Alpha or Beta according to their degree of literacy. Those who fail in Alpha are given Beta, and those who fail to pass Test Beta are given an individual test.