20 THE M I N D O F TH E BUY E R
(^1920) th e n umb e r h a d i nc re ased to seventy-six
pe r c en t. ( S e e Fig.
An oth e r illustra tion of th e “ hi sto ric al
meth od : A numbe r o f fi rm s desi re d to deter
mi ne th e best m e th od of sel ec ting sal e sm en.
F IG. 4. Showing the increase in the use o f lower-case
type for hea dlines between 1 905 and (^1920).
Th ey form e d a c oo pe ra tive burea u which
examined th e p rac tic e s of all th e fi rm s ; t abu
l at e d th em an d c ombined th e re sul ts, emb ody
in g th e m i n to a syste m by which all migh t
sel ec t th eir sal esm en.
In empl oyi ng th e “ his tori cal” m e th o d we
m ake use o f several a ssum pti on s