SELECTION OF EXAMINATIONS 77
What, then, are the characteristics of a good test? And
where should the investigator search for suitable test
materials?
PRINCIPLES GOVERNING THE SELECTION AND
CONSTRUCTION OF TESTS
Objectivity. Foremost among the characteristics of a
scientific test is that it yields objective measures. Opinion,
individual judgment, and the personal equation of the
examiner who gives or scores the test should be reduced to
a minimum.
Research procedure in vocational selection has for its
purpose the provision of something better than mere
hunches or unanalyzed general impressions as a basis
for decisions and recommendations. The outstanding char-
acteristic of the unscientific methods is their lack of ob-
jectivity. An interviewer who relies on subjective impres-
sions or indefinable intuitions is dependent upon his alert-
ness, his previous experience, and his social sensitivity, He
never knows when or how much he can trust his hunches.
Moreover, interviewers differ widely in their ability to arrive
at a fair estimate of an applicant through general impres-
sion. Their judgments tend to be at variance because of
personal prejudices, differences in ability to judge, and
failure to agree upon the vital point most essential for the
job. A few rare employment interviewers seem to be very
successful although relying on their unanalyzed subjective
impressions. But no business concern wishes to be depen-
dent upon a rarely gifted person who cannot readily be re-
placed. The purpose of the investigator is to bring to light
the abilities and characteristics of a worker which the suc-
cessful interviewer judges in the applicant, and to measure
them accurately by a method which can then be used with
equal success by any carefully trained examiner. For in-
tuitive opinion he substitutes objective tests.