PSYCHOLOGICAL TESTS 3
fruitful source of information on the technique of perfor-
mance tests. The job apparatus suggests materials.
Some well-known performance tests are steadiness, tap-
ping, tracing, card-sorting, picture completion, form board,
maze, puzzle box, manipulation, assembly or construction
of a mechanical object of which the parts are given (Sten-
quist test, Kelley contruction test), and the newer tests of
personality in which a social situation is set up by making
the examiner an integral factor in the apparatus (119).
An example of a test of the latter sort is to be found on page
118.
Some illustrative performance tests are shown in F igures
5, 6, 7, and 8.
Explanation of Compound Slide Rest Test (Figure 5). This
apparatus consists of a small traveling platform which is made
to move in any desired horizontal direction by means of two
screws placed at right angles to each other. The direction of
movement of the platform is governed by the relative speed with
which the screws are rotated. A pencil is placed loosely in a
clamp so that its point rests on a piece of paper mounted on the
platform. The subject is required to move the platform in such
a way as to cause the pencil to trace the outline of a diagram on
the piece of paper. The diagram may consist of parallel or con-
centric lines forming a track. The person tested is instructed to
keep within the track and proceed as fast as he can. Each digres-
sion of the line outside the track is recorded as an error.
Tagg (181) compared performance in this test with trade
ranking, using as subjects young men in training for various
trades at a technical school. He reports the following correlations
between test performance and trade ability.
Draftsmanship ..........cvsex 142
TOarning ... 0. «coi viie deviate oid 200i
PRUNE Louvain ich ve al
Patternmaking .............. %4
Machine-operating ........... .3-
[Boolmaking ....., . o. u. lhl JE
Dr. J. L. Prak, psychologist at the Philips Lamp Works, Eind-
hoven, Holland, using this test with three groups of boys at a
trade school, obtained correlations of 46, .32, and .53 with trade
ability as judged by teachers.
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