EMPLOYMENT PSYCHOLOGY
the well-known psychological tests, but to use any promising
measuring device which may be made to conform to the
principles set down in this and the preceding chapter. Proof
of relationship between a series of measurements and success
 in an occupation makes that series of measurements,
regardless of its origin, a matter of interest and value.
Specialists in the selection of employees have installed systems
 with a total disregard for scientific methods of validating
 their results. Scientists who have evaluated the work of
these persons have found most of it worthless. But some of
these systems and tests show originality and, if applied with
scientific care, might reward the investigator. If, on the
other hand, they prove worthless, the investigator who has
checked them scientifically instead of dismissing them without
 a hearing has a weapon with which to combat their
advocates.
The following chapters deal with the details of the construction
 of psychological tests, rating scales, and questionnaires.


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