ly defined.

XIV, 2. INDUCTION TEST: FINDING A RULE

PROCEDURE. Provide six sheets of thin blank paper, say 81/2 x 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.

Continue in the same manner with sheets four, five, and six, adding one
fold each time. In folding each sheet recapitulate the results with the
previous sheets, saying (with the sixth, for example): "_When we folded
it this way there was one hole, when we folded it again there were two,
when we folded it again there were four, when we folded it again there
were eight, when we folded it again there were sixteen; now, tell me
how many holes there will be if we fold it once more._" In the
recapitulation avoid the expression "_When we folded it once, twice,
three times_," etc., as this often leads the subject to double the
numeral heard instead of doubling the number of holes in the previously
folded sheet. After the a