PSYCHOLOGICAL FACTORS IN VOCATIONAL GUIDANCE 149 
already been handed over from the vocational counsellors to the 
experimental psychologists.’’ In his mind, ^Hhe laboratory 
method” was as superior to the ^^mere-impression” method as 
^Hhe microscope is superior to the human eye.” As a rule the 
investigators in this line are more moderate in their claims and 
expectations, and for the two reasons, namely that (1) the 
technique of mental measurement is not so highly perfected as 
the microscope and (2) the material to be dealt with is of the 
most complex kind. 
The committee on vocational guidance appointed by the 
National Education Association makes a * three-fold classifi- 
cation of the experimental work being carried on by the voca- 
tional psychologist, namely: 
(1) The attempt to supply the employer with tests that will enable 
him to select from a large number of applicants those most likely to 
succeed in a given position (vocational selection) ; (2) the attempt to 
determine specific vocational abilities — that is, which of several occu- 
pations would be the best one for a given individual to follow; (3) the 
attempt to develop tests for the measurement of general intelligence. 
Professor Muensterberg, who was one of the first men in this 
country to go at the matter of vocational guidance laboratory 
fashion, performed experiments to weed out applicants and also 
to discover personal aptitude. His tests (which were not of the 
general intelligence variety, but were tests of reaction time, 
association, attention, etc.) were applied, as he said, from the 
side of ^The scientific manager who seeks the best man for the 
work; and from the side of the vocational counsellor who seeks 
the best work for the man.” He thought that by so doing the 
interests of both sides were provided for. Being a pioneer in 
this new world of discovery, Muensterberg did not blaze the 
way very far, but what he did was of practical value and rather 
significant. His investigations were concerned with finding out 
what sort of equipment was required of a person who could be 
counted on to succeed as a typesetter, a motorman, a telephone 
operator, etc. His methods and results in the case of -the motor- 
man are typical. Assuming that for motormen on street rail- 
