EMPLOYMENT PSYCHOLOGY
process. It supplements the tests and other measures of
ability. This is a common procedure in the selection of
candidates for training as salesmen.
If the subjects are old employees, ratings are usually
obtained from foremen and supervisors. In the employment
office, however, ratings must be made by the interviewer or
examiner, by the applicant’s references, or even by the applicant
 himself. Even though a series of ratings by foremen
may prove to be valid, the investigator is left in doubt as to
the validity of ratings on these same abilities when made by
the interviewer on the basis of a brief talk with the applicant.
 It is essential, therefore, to validate ratings by interviewer
 and applicant, as well as by supervisors or fellow
workmen.
The experimental rating scale may cover a good many
items. A scale installed for permanent use in the employment
 office should be kept within practical length. It should
include only the reliable and valid items.
Ratings should not be included on abilities or characteristics
 which can be objectively measured by tests or personnel
records. Do not ask a foreman to rate his men on attendance
 or tardiness when the facts are matters of record.
The rating scale which the investigator develops is seen
to serve as a substitute gage of abilities for which no adequate
 objective tests are available. Besides its uses in employment,
 it will help in deciding questions of transfer and
promotion, in discovering need for special training, in measuring
 progress in this training, and in passing upon recommendations
 at periods of salary readjustment.
This measuring implement, the rating scale, is generally
recognized to be at best a crude tool. Its reliability is low.
Its scope is limited. Nevertheless, it is distinctly better
than no instrument at all, and this in itself is a justification
for the wide use it has found in industry.
Tt now remains to consider the third form of examination
—the questionnaire.

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