EMPLOYMENT PSYCHOLOGY
certain point about this procedure is that nothing is known
of the tested ability of the proved failures. They might
make the same scores as the experts! No differentiation in
test performance between experts and failures is proved.
We may then conclude that the best way to choose subjects
 for testing is to select workers already known to be
competent or incompetent, provided the extremes of ability
as well as the middle ranges are available in sufficient numbers,
 and provided the group is in other respects sufficiently
homogeneous, or sufficiently large to make possible a statistical
 control of disturbing variables.
Where the number of experienced employees is too few,
or too uniform in ability to yield a sufficient range in the
criterion of vocational success, measurement of new
workers at the time of employment is indicated. Except
for the disadvantage of protracting the investigation, this
procedure will commend itself for the reasons already
stated. Applicants should be hired for experimental purposes
 regardless of their test scores.
GENERAL CONSIDERATIONS
No man should take the tests under compulsion. If anyone
 fails to respond to persuasion, the investigator will do
well to let the matter rest. When the Jthers have been
tested, the obstinate person is apt to ask for an examination.
Any person should be rejected as a subject who is already
familiar with the tests or other measuring instruments.
Occasionally a supervisor or other minor executive whose
men are being examined will ask that he also be given an
examination. The investigator will find it advisable to refuse
 all special requests, with the explanation that since the
tests are still in the experimental stage and nothing is
definitely known of their value, the scores will be meaningless.

The scores made by individual workers during the experimental
 period of test development and standardization

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