EMPLOYMENT PSYCHOLOGY DEFINED 
17 
You would not—not if you expected to hold your job. 
And yet, that is what you are doing with respect to the 
public education system of California. In 1916 the rail 
roads of this state paid in operative taxes $7,151,583. 
Of this sum 51 per cent, or $3,647,300, was used for pur 
poses of public education, 'The boys and girls sent you 
from, the public schools you take into your service, sometimes 
after a perfunctory mental examination, generally with none; 
in other words, you waive inspection, and then complain 
of the character of the material after it has reached you 
and been paid for.” 
What has psychology done to solve these problems 
and to introduce into the employment methods of to 
day a more scientific procedure? The greatest single 
contribution of scientific psychology to the solution of 
this problem has been the application of mental tests. 
A mental test is a device, similar to a measuring instru 
ment in any of the sciences, by which certain mental 
activities can be accurately measured. The use of mental 
tests is not absolutely new or unfamiliar. All formal 
examinations may be regarded as coming under the gen 
eral category of mental tests. A written examination 
which is absolutely alike for all those taking it, and for 
which every person is allowed exactly the same amount of 
time, is a good example of tests in general. Such tests 
have been used quite commonly in schools, as require 
ments for entrance into college, and for similar purposes. 
The civil-service system is a good example, outside of the 
field of psychology, of the development of standard men 
tal tests. The civil-service tests are standardized for all 
parts of the country and are given under conditions that 
approach uniformity. This is what gives them their 
value. It is evident, therefore, that the use of psycholog-