EMPLOYMENT PSYCHOLOGY DEFINED I9 
of the work as it is actually being done. Its laboratory 
is the shop and the office. The conditions under which 
it conducts its experiments are the actual conditions and 
not the highly artificial and theoretical conditions entailed 
by the stereotyped psychological laboratory. The employ 
ment psychologist must find and apply mental tests to 
employees on the basis of a study of the work which they 
are doing. In fact, he must become an employee himself, 
in order that he may understand the kind of mental action 
for which he is trying to find tests or measures. Only the 
most temerarious psychologist would attempt to devise 
or apply tests to employees whose work he understood in 
only a superficial fashion. 
There is a very decided tendency to-day to make a wide 
spread and wholesale use of tests for employment purposes. 
Newspapers and periodicals have given much space to the 
description of tests and have made many sensational and 
extravagant claims for their usefulness. There is great 
danger in a sudden and extensive application of tests. 
Indeed, ridicule has already been provoked by their indis 
criminate use; for anyone with a little ingenuity, whether 
he be a psychologist or not, can take a ready-made psy 
chological test and apply it, after a fashion. But, having 
applied it, the chief difficulty remains, namely, how shall 
it be interpreted? What does it mean? No test has any 
significance for employment purposes until it has been 
tried out (by the scientific process to be described later) 
on employees doing exactly the same kind of work as 
that for which new applicants are to be tested later on. 
If, for instance, an employment manager receives a set 
of trade tests or clerical tests for use in connection with 
the selection of workers, he can not use those tests effec 
tually until a trained psychologist has tried them out on