This preliminary sampling affords a means of checking on the following points:
1. Is the test applicable to trade conditions?
2. Does the test represent good trade practice?
3. In what way can parts be profitably modified, supplemented, or eliminated?
4. Does the test represent the whole range of the trade, from the novice to the expert?
5. Is it a representative sampling of the whole range of trade processes?
In the light of the answers to these questions, the test is revised during this sampling process and is then ready to be formulated. This formulation consists of limiting the questions to a small enough number to be handled in a short space of time and to a wide enough range to represent every possible degree of trade skill. The questions are tabulated and are then ready to be used in the final sampling process.
Final sampling is made by testing twenty men who are known to be typical representatives of each group (novice, apprentice, journeyman, expert). Among the novices tested are some highly intelligent and mature men of good general knowledge but no trade ability. Three testing stations were used in the Army’s work: one in Cleveland, one in Newark, and one in Pittsburgh, in order to get the benefit of wide geographical distribution. Examinations were given to men whose record in the trade was already known and who were tested as nearly as possible in the same manner as men in the camps.
The results of this final sampling are turned over to experts who make a careful study of the results and of the answers to each question. This enables them to determine the relative value of each individual question and the selection that makes a proper balance.
If a trade test is good, a known expert, when tested, is able to answer all, or nearly all, the questions correctly; a journeyman is able to answer the majority; an apprentice a smaller part, and a novice practically none. This does not mean that each question should be answered correctly by all the experts, a majority of the journeymen, some apprentices but no novices. There are a few questions which show this general result. A graphic curve when plotted for such a question is almost a straight line.