simple {276} to serve as a test for intelligence, but the young
child finds it difficult, and the mentally deficient adult goes at it
in the same haphazard way as a young child, trying to force the square
block into the round hole. He does not pin himself down to the one
essential thing, which is to match blocks and holes according to
shape.

Another good performance test is the "picture completion". A picture
is placed before the child, out of which several square holes have
been cut. These cut-out pieces are mounted on little blocks, and there
are other similar blocks with more or less irrelevant objects pictured
on them. The child must select from the whole collection of little
blocks the one that belongs in each hole in the picture. The better
his understanding of the picture, the better his selection.

Group Testing

The tests so far described, because they have to be given to each
subject individually, require a great deal of time from the trained
examiner, and tests are also needed which can be given to a whole
group of people at once. For persons who can read printed directions,
a group test can easily be conducted, though much preliminary labor is
necessary in selecting and standardizing the questions used. Group
testing of foreigners, illiterates, and young children is more
difficult, but has been accomplished, the directions being conveyed
orally or by means of pantomime.

The first extensive use of group intelligence tests was made in the
American Army during the Great War. A committee of the American
Psychological Association prepared and standardized the tests, and
persuaded the Army authorities to let them try them out in the camps.
So successful were these tests--when supplemented, in doubtful cases,
by individual tests--that they were adopted in the receiving {277}
camps; and they proved very useful both in detecting those individuals
whose intelligence was too low to enable them to learn the duties of a
soldier, and those who, from high intelligence, could profitably be
trained for officers.

The "Alpha test", used on recruits who could read, consisted of eight
pages of questions, each page presenting a different type of problem
for solution. On the first page were rows of circles, squares, etc.,
to which certain things were to be done in accordance with spoken
commands. The subject had to attend carefully to what he was told to
do, since he was given each command only once, and some of the
c