“This is Test 4 _here_. Look.” After everyone has found the page—“Now watch.” E. points to first digit of key on blackboard and then points to the symbol under it. Same for all nine digits in key. E. then (1) points to first digit of sample, (2) to the empty space below digit, (3) points to corresponding digit of key, (4) points to proper symbol under digit in key, and (5) traces the outline of the proper symbol in the blank space under the digit in the sample. Same for first five samples. Demonstrator, at a gesture, fills in all the samples, working as follows: (1) Touches the number in first sample with index finger of right hand; (2) holding finger there, finds with index finger of left hand the corresponding number in key; (3) drops index finger of left hand to symbol for number found; (4) holding left hand in this position writes appropriate symbol in the lower half of sample. [Illustration: Test 4] Similarly with the other samples. While working, demonstrator should stand as far as possible to the left, doing all the samples from this side. At the end of demonstration E. says, “Look here” and points to key on page, repeating the gestures used in pointing on the blackboard at the beginning of the demonstration. Then, “All right. Go ahead. Hurry up!” Orderlies point out key to men who are at a loss to find it. At the end of 2 minutes, E. says: “Stop! But don’t turn the page.” TEST 5—NUMBER CHECKING “This is Test 5 _here_.” After everyone has found the page, “Now watch.” In this demonstration E. must try to get “Yes” or “No” responses from the group. If the wrong response is volunteered by group, E. points to digits again and gives right response, “Yes” or “No” as the case may be. E. points to first digit of first number in left column, then to first digit first number in right column, then to second digit first number in left column and second digit first number in right column; nods head, says “Yes” and makes an imaginary cross at end of number in right column. Motions to demonstrator, who makes an “X” there. E. does the same for second line of figures, but here he indicates clearly by shaking head and saying “no” that certain digits are not identical. E. repeats for three more sets and after each, looks at group, says “Yes?” in questioning tone and waits for them to say “Yes” or “No.” He repeats correct reply with satisfaction. Demonstrator checks each after group has responded, or at signal from E. if group does not respond. Demonstrator then works out remaining items, pointing from column to column and working deliberately. E. summarizes demonstrator’s work by pointing to the whole numbers in each set and saying “Yes” (indicating X) or “No”; if “No,” he shows again where the numbers are unlike. E. then points to page and says “All right. Go ahead. Hurry up!” At the end of 3 minutes E. says “Stop! Turn over the page to Test 6.” =Test 5=