It  will  be  the  purpose  of  the  next  two  exercises
to  undertake  an  experimental  analysis  of  certain
typical  cases  of  practice,  and  to  study,  in  this  way,

92


OF


FOgil-^  IMPRESSION   FACTORS


93

the  changes  produced  hy  development  in  the  rela-
tions between  various  factors  of  experience.  Such
an  analysis  will  show  in  certain  cases  that  the  chief
improvement  has  been  in  apprehending  more  fully
and  organizing  more  completely  the  sensory  fac-
tors. In  other  cases  it  will  be  found  that  it  is
chiefly  the  relation  between  the  motor  factors  which
is  modified  through  practice.  In  a  third  type  of
eases,  the  sensory  factors  and  the  motor  coordina-
tions are  not  especially  modified,  but  the  relation
between  sensations  and  motor  processes  is  changed
during  the  practice  series.
Such  exercises  as  these  will  serve  to  reenforce
the  teachings  of  the  foregoing  exercises,  that  ex-
perience is  dependent  on  both  motor  and  sensory
conditions.  To  be  sure,  the  time  available  for  such
exercises  as  can  be  taken  up  in  this  course  makes
it  impossible  to  follow  the  processes  of  develop-
ment under  discussion  very  far.  For  more  com-
plete studies,  reference  may  be  made  to  the  follow-
ing typical  researches :

Bryan  and  Harter,  *'  Psychological  Review,"  vol.  vi
(1899),  p.  346.
Swift,  "  American  Journal  of  Psychology,"  vol.  xiv
(1903),  p.  201.
Cameron  and  Steele, "  Yale  Psychological  Studies,"  New
Series,  vol.  i,  p.  83.
94  PSYCHULOGY

Of  the  two  exercises  here  outlined,  the  first  will
not  require  any  change  in  the  relation  between
the  factors  of  the  movement  involved,  but  will
deal  chiefly  with  the  relation  of  sensory  factors
to  practice.
