EMPLOYMENT PSYCHOLOGY 
5 6.00 
5.72, 
1922 
1925 
wa Fev., wear nr. 1923 1924 1925 
fe Jl - 
Figure 32: Proportion of accidents Figure 33: Proportion of accidents 
per mile driven for first four months per mile driven for the first four 
of 1923, 1924, and 1025. months of the vear. 
Data from the Yellow Cab Company, Chicago Illinois (170). Psycho- 
logical tests of applicants for positions as driver were installed in January, 
1925. The improved method of selection brought about a substantial 
decrease in accidents per mile driven. The exact figures are not given on 
the scale. Relative position only is indicated. 
tation of such findings are given in Figures 32, 33, and 34. 
Vigilance is the price of exact measurement in vocational 
selection. It is not enough that a carefully planned investi- 
gation is carried out by a trained man and that valid and 
economical measuring instruments for selection are produced 
and put to use. To assure to both workers and manage- 
ment the benefits of such scientific procedures, continued 
oversight by a competent industrial psychologist is essential. 
This volume has outlined the scientific methods which 
investigators, in touch with the practical demands of modern 
business and industry, have at their disposal for increasing 
the reliability of prediction of an applicant’s future com- 
petence and satisfaction in his work. 
Few will question that substantial improvements in the 
process of vocational adjustment which these scientific pro- 
cedures make possible are of both economic and social im- 
220