oo EMPLOYMENT PSYCHOLOGY
ingenuity of the more successful direct-mail copy-writers is
needed to insure a maximum proportion of replies. Questionnaires
to be sent by mail should be exceptionally brief
and should be accompanied by a tactful letter explaining the
nature of the inquiry and the service which can be done the
applicant by giving correct and conscientious answers. The
same letter may enclose a rating scale. An example of such
a letter and rating scale is given in Figures 17 and 18.
It pays to follow up an inquiry. Toops (203a¢) made a
careful study of questionnaires sent out to graduates of a
trade school, to determine the success of the instruction.
By the use of five follow-up letters in addition to the one
originally sent with the questionnaire, he succeeded in obtaining
completed questionnaires from 93% of the graduates
whom he was able to reach by mail. The cost per reply
from the first letter was $2.77; the final cost per reply of all
returns was 68 cents. Among the most important points
he makes are the following: There was no great difference
between the data from those who replied at once and from
those who required a large number of follow-up letters to
arouse them to reply; in other words, those who reply
readily are not a biased sampling. The shorter the questionnaire
the better are the chances of getting replies. The
cost per return will be decreased by continuing to send
follow-up letters until practically all the questionnaires are
returned. When the curve of cumulative returns from a
mail canvass becomes almost horizontal, it is time for another
follow-up letter. The week-end holiday is the time
when recipients are most likely to fill out questionnaires, and
mail should reach them toward the end of the week. The
letters which Toops used, printed in full in his article, will
suggest ways of wording such letters in order to insure sufficient
replies.
The telephone is better than the mail in checking the
worker’s statements and in obtaining information from his
references. Data may also be obtained by company in-552
