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EMPLOYMENT PSYCHOLOGY
practice. This practice should be written up in the most
detailed and accurate form, and illustrated with examples
so far as possible, so that other examiners, giving the same
test and using the same directions, may likewise be giving
the same demonstration and thereby obtaining the same
standard results. As a supplement to this step, it is
always advisable to give the subject a short preliminary
trial in the test which he is about to take. Only in this
way can the examiner be sure that his directions have
been fully comprehended. To the unsophisticated mind,
it may seem sufficient if the examiner, after having given
the directions as clearly as possible, asks the subject:
“Now do you understand?” and, upon receiving the
answer “Yes,” proceeds with the test. However, no
matter how intelligent the subject may appear, it is never
safe for the psychologist to assume that his directions are
grasped until he has had an actual preliminary demonstration
on the part of the subject showing that they are.
Many subjects only think that they understand, when, as
a matter of fact, they do not; or they understand the
wrong thing. Therefore, it is always advisable to give a
very short, but characteristic sample of the test, in order
to insure perfect comprehension on the part of the person
being examined. This sample should always be of the
same length and kind, to insure every subject the same
degree of instruction and practice.
Sometimes it is impossible to make the directions for a
test clear enough. In that case, the difficulty probably
lies with the test itself. This was the case in the Bogardus
fatigue test described in Chapter X. The number of
reactions made possible by this test were so numerous and
variable, that it was also impossible to score the results.
In such a case, it is necessary either to give up the test of
