The performance tests are now being used in many trades for those who make a satisfactory showing in the oral or picture tests. These performance tests are devised by conference with experts in the trade. They consist of some apparently simple tasks that can be performed quickly and with a small amount of apparatus but that nevertheless indicate clearly the degree of skill of the performer. As a result of experience the following have been drawn up as the requirements for a good performance test: 1. It should require the smallest possible quantity of tools and materials and these should be capable of standardization; 2. A journeyman should not require more than 45 minutes to perform it; 3. It should be typical of the work required; 4. The operations should be exact so that a correct standard form of product is always obtainable. Performance tests undergo much the same processes of sampling as do the oral and picture tests and they are calibrated in the same way. The principle followed here, as elsewhere, is that the value of a test lies not in its theoretical exactness but in its proved ability to pick out and classify correctly men of all degrees of skill within the trade. If the test does classify men in the groups in which they are known to belong, then it can be relied upon to classify correctly men about whom nothing is known in advance. The method which the Army pursued is adaptable for any private enterprise. The work done under the direction of the Army General Staff in analyzing the essentials of nearly seven hundred trades and subdivisions of trades and in preparing tests for a large proportion of these was pioneer work, the results of which, in the shape of the tests themselves, while not issued for general distribution, are available as a time-saving guide to those who are interested in the building and application of trade tests. APPENDICES APPENDIX A INTELLIGENCE RATINGS IN THE ARMY Reprinted from The Personnel Manual (Vol. II of The Personnel System of the United States Army) _Purpose of the Intelligence Tests._—Under the direction of the Division of Psychology, Medical Department, and in accordance with provisions of General Order No. 74, mental tests are given all recruits during the two-weeks detention period. These tests provide an immediate and reasonably dependable classification of the men according to _general intelligence_. Their specific purposes are to aid:— (1) In the discovery of men whose superior intelligence suggests their consideration for advancement; (2) In the prompt selection and assignment to Development Battalions of men who are so inferior mentally that they are suited only for selected assignments; (3) In forming organizations of uniform mental strength where such uniformity is desired;