EMPLOYMENT PSYCHOLOGY 
subject of rating scales is taken up in Chapters IX and X. 
Ratings are more often useful as criteria of success of 
executives and salesmen than of operatives engaged in rou- 
tine tasks requiring manual skill. Objective criteria of 
manual skill are more likely to correlate with objective per- 
formance tests, and ratings are more likely to correlate with 
tests of personality. 
Ratings may be made on the single characteristic of suc- 
cess in the occupation; or they may be distributed over 
a combination of several abilities which are deemed neces- 
sary to success in the occupation, and the sum used as a 
judgment on vocational success. But the safer procedure 
in obtaining a criterion of success is to ask for ratings on 
success, using the ratings on component abilities required 
for success at a later time as checks on the investigator’s 
analysis of these abilities. 
If ratings are adopted as criteria, use should be made 
of a final rating which is the unweighted average of the 
independent judgments of at least three intelligent unbiased 
men who are thoroughly acquainted with the persons to be 
rated and who are given plenty of time in which to make 
their judgments. The reliability of this criterion should be 
determined by asking each judge to rate the men again at a 
later date. 
Executives who are skeptical about psychological tests 
sometimes insist on the use of their personal estimate of 
their subordinates as a measure of success. In this case 
one compensation attaches to the use of ratings as criteria, 
namely, that if a correlation is established between criterion 
and tests, the proof of the value of the tests is brought home 
in a very personal way to the executive who makes the rat- 
ing. 
GENERAL CONSIDERATIONS 
If the investigator believes that any one of the available 
criteria taken alone is inadequate to express the employee’s 
vocational accomplishment, there is no reason why several 
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