that folding the paper again will again double the
number. The ability tested is the ability to generalize from
particulars where the common element of the particulars can be discerned
only by the selective action of attention, in this case attention to the
fact that each number is the double of its predecessor.

XIV, 3. GIVING DIFFERENCES BETWEEN A PRESIDENT AND A KING

PROCEDURE. Say: "_There are three main differences between a president
and a king; what are they?_" If the subject stops after one difference
is given, we urge him on, if possible, until three are given.

SCORING. The three differences relate to power, tenure, and manner of
accession. Only these differences are considered correct, and the
successful response must include at least two of the three. We disregard
crudities of expression and note merely whether the subject has the
essential idea. As regards power, for example, any of the following
responses are satisfactory: "The king is absolute and the president is
not." "The king rules by himself, but the president rules with the help
of the people." "Kings can have things their own way more than
presidents can," etc.

It may be objected that the reverse of this is sometimes true, that the
king of to-day often has less power than the average president.
Sometimes subjects mention this fact, and when they do we credit them
with this part of the test. As a matter of fact, however, this answer is
seldom given.

Sometimes the subject does not stop until he has given a half-dozen or
more differences, and in such cases the first three differences may be
trivial and some of the later ones essential. The question then arises
whether we should disregard the errors and pass the subject on his later
correct responses. The rule in such cases is to ask the subject to pick
out the "three main differences."

Sometimes accession and tenure are given in the form of a single
contrast, as: "The president is elected, but the king inherits his
throne and rules for life." This answer entitles the subject to credit
for both accession and tenure, the contrast as regards tenure being
plainly implied.

Unsatisfactory contrasts are of many kinds and are often amusing. Some
of the most common are the following:--

"A king wears a crown." "A king has jewels." "A king sits on a
throne." ("A king sets on a thorn" as one feeble-minded boy put
it!) "A king lives in a palace." "A king has courtiers." "A king
is