EMPLOYMENT PSYCHOLOGY 
sequence of jobs but the time employed at each, and the 
length of periods of unemployment. 
It is essential that the work be described in enough detail 
to permit accurate identification of the job held. “Sales- 
man,” “machine operator,” “teacher,” “electrician” are not 
definite enough. A worker who had once been employed 
with the title of electrician was found on further question- 
ing to have had no duties more technical than turning the 
electric lights on and off in a motion-picture theater. “Just 
what did you do?” is the question which should be repeatedly 
pressed for precise answer. 
When it is possible to learn how well the worker succeeded 
at these various occupations, the way is opened to a study 
of the predictive value of different sorts of experience, with 
reference to success in the occupation being investigated. 
Even without any index of relative success in previous jobs, 
some useful facts may be uncovered with reference to pre- 
ferred types of previous experience. Even so simple a 
measure as average length of time on previous jobs has 
been found to have some validity in forecasting stability on 
routine work. 
4. Education and training. Data on these subjects are 
easily obtained either from the records of the employment 
office or by questionnaires. They should cover informal as 
well as formal education, night-school and extension work 
as well as regular courses, avocational as well as vocational 
education. School marks and other evidences of school 
accomplishment may be worth getting if the investigator 
knows the standards of the schools and of the instructors 
concerned. 
Rate of progress through school is almost as accurate a 
measure of intelligence as a good mental alertness test. For 
this reason the application blank or questionnaire should 
include the items “age at leaving school,” and “grade 
reached.” This information is unreliable unless checked in 
personal interview. It is impossible to secure it from many 
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