While there are all degrees of trade ability among the members of any trade, it is convenient to classify them in a few main groups. Ordinarily the terms Novice, Apprentice, Journeyman, and Journeyman Expert (or Expert) are employed. The Novice is a man who has no trade ability whatever, or at least none that could not be paralleled by practically any intelligent man. The Apprentice has acquired some of the elements of the trade but is not sufficiently skilled to be entrusted with an important task. The Journeyman is qualified to perform almost any work done by members of the trade. The Expert can perform quickly and with superior skill any work done by men in the trade. It is sometimes desirable that the Trade test should differentiate between the skill of different members of the same group, for instance, of the journeyman group. It is essential that it should differentiate between the journeyman and the apprentice and the apprentice and the novice. Trade tests devised to make this classification are of three kinds: oral, picture, and performance. The oral tests are most generally used because they are of low cost and they may be applied to a large number of men in a comparatively short time and without much equipment. They are satisfactory in determining the presence or absence of trade ability and in many instances determine the degree of ability with such accuracy that no other tests are required. As a preliminary to the preparation of a trade test, there is required a thorough inquiry into the conditions of the trade. This inquiry has a threefold purpose: 1. To determine the feasibility of a test in this field. Does the trade actually exist as a recognized trade? It was found, for example, that the trade of gunsmith was not a recognized trade, though there were gun repairers. 2. To determine the elements which require and permit of testing. In other words, can men be graded in it according to degrees of skill? In some trades it was found that the trade required simply the performance of a single set of operations and there were no gradations among the members of the trade. 3. To determine the kinds of tests that can be used. Some trades, such as truck driving and typewriting, are mainly matters of skill, and for them performance tests are better than oral tests. Other trades, such as interior wiring and power-plant operation, are mainly matters of knowledge. For these trades oral and picture tests are best. After having discovered by inquiry that the trade is a recognized trade and can be tested, information is collected from all available sources. In the Army’s preparation of trade tests experts in the trade, trade union officials, the literature of the trade, trade school authorities, employers, and the like were consulted. In this way it was discovered what are the elements of the trade and what constitutes proficiency in it.