_Satisfactory._ "All are plants." "All grow from the ground." "All have leaves" (or roots, etc.). "All have to be planted." "All are parts of nature." "All have colors." _Unsatisfactory._ "All are pretty." "All bear fruit." "All have pretty flowers." "All grow on bushes." "All are valuable" (or useful). "They grow close to a house." "All are ornamental." "All are shrubbery." REMARKS. The words of each series lend themselves readily to classification into a next higher class. This is the best type of response, but with most of the series it accounts for less than two thirds of the successes among subjects of 12-year intelligence. The proportion is less than one third for subjects of 10-year intelligence and nearly three fourths at the 14-year level. It would be possible and very desirable to devise and standardize an additional test of this kind, but requiring the giving of an essential resemblance or classificatory similarity. For discussion of the psychological factors involved in the similarities test, see VII, 5. CHAPTER XVIII INSTRUCTIONS FOR YEAR XIV. XIV, 1. VOCABULARY (FIFTY DEFINITIONS, 9000 WORDS) PROCEDURE and SCORING, as in VIII, X, and XII. At year XIV fifty words must be correctly defined. XIV, 2. INDUCTION TEST: FINDING A RULE PROCEDURE. Provide six sheets of thin blank paper, say 8½ × 11 inches. Take the first sheet, and telling the subject to watch what you do, fold it once, and in the middle of the folded edge tear out or cut out a small notch; then ask the subject to tell you _how many holes there will be in the paper when it is unfolded_. The correct answer, _one_, is nearly always given without hesitation. But whatever the answer, unfold the paper and hold it up broadside for the subject's inspection. Next, take another sheet, fold it once as before and say: "_Now, when we folded it this way and tore out a piece, you remember it made one hole in the paper. This time we will give the paper another fold and see how many holes we shall have._" Then proceed to fold the paper again, this time in the other direction, and tear out a piece from the folded side and ask how many holes there will be when the paper is unfolded. After recording the answer, unfold the paper, hold it up before the subject so as to let him see the result. The answer is often incorrect and the unfolded sheet is greeted with an exclamation of surprise. The governing principle is seldom made out at this stage of the experiment. But regardless of the correctness or incorrectness of the first and second answers, proceed with the third sheet. Fold it once and say: "_When we folded it this way there was one hole._" Then fold it again and say: "_And when we folded it this way there were two holes._" At this point fold the paper a third time and say: "_Now, I am folding it again. How many holes will it have this time when I unfold it?_" Record the answer and again unfold the paper while the subject looks on.