24 
EMPLOYMENT PSYCHOLOGY 
girls would correspond with their daily production or 
output of shells. If it could be demonstrated that the best 
workers did best in certain tests, and that the poorest 
workers did the poorest work in these tests, then it would 
be reasonable to assume, subject to further proof or dis 
proof, that these tests gave a reliable indication of the 
workers’ ability at inspection. And it would further be 
reasonable to assume that these tests, given to applicants 
whose ability as inspectors was an unknown quantity, 
would enable the employment office to select those who 
had certain qualities necessary for success at this work. 
Only those applicants who showed a certain degree of 
skill in these tests would be selected for the type of work 
on which these tests had been found significant. This, in 
brief, is the method of trying out tests, the details of which 
will become clear in the course of the experiment. 
After the type of work for this experiment had been 
decided upon, the next step was to make a careful and in 
tensive study of the qualifications involved in doing that 
work. The work of inspecting shells was done at a table 
like an upturned shallow box. Upon this hollow table 
was dumped a large box of brass shells, not yet loaded, 
and all of exactly the same kind. The work of each girl 
was to inspect these shells and throw out those that were 
defective. In doing this, a girl would first gather up a 
large handful of shells, as many as could be piled in one 
hand, being careful to have all of them pointing in the 
same direction. Then she would put both hands around 
the shells and turn them all up so as to expose their in 
sides. She would then look down into every shell for 
dents, scratches, stains, and other very minute defects. 
When any such defect was discovered, the shell was skill 
fully extracted from the pile and thrown into one of three