MACHINE  OPERATORS

n 5

f as e,  the  speed  at  which  the  apparatus  worked  made
almost  impossible  even  to  see  the  cube’s  position  after
lt:  had  been  placed;  for  the  arm  would  cover  the  cube  before ­
  the  hand  could  be  taken  away.  Sometimes,  the  hand
Was  not  taken  away  quickly  enough  and  the  revolving
arm  collided  with  it,  slowing  down  its  revolution.  This
w °uld  still  further  increase  the  difficulty  of  scoring.  Add
to  this  the  fact  that  it  required  the  experimenter’s  entire
a ttention  to  keep  the  apparatus  moving  properly,  and  it
be  seen  that  the  difficulties  of  obtaining  a  proper  score
0n  an  individual’s  performance  were  almost  insurmountabIe
 -  This  difficulty  naturally  deprived  the  apparatus  of
^uch  of  its  value  as  a  test.  A  third  important  drawback
the  difficulty  of  revolving  the  arms  at  speeds  which
'''ere  both  constant  and  readily  adaptable  to  the  purposes ­
  of  the  test.  The  electrical  control  which  was  tried
w as  found  much  too  troublesome  and  expensive  for
the  purpose.
spite  of  these  difficulties,  it  seemed  as  if  the  principle
^  the  test  were  correct  and,  therefore,  it  was  decided  to
esig n  a  s i m q ar  apparatus  which  would  obviate  the  difficulties ­
  found  in  the  original.  In  designing  this  test,  the
step  was  to  find  out  exactly  what  kind  of  work  maim ­



st

chine

operators  were  doing.  It  seemed  unreasonable  from

e  outset  to  assume  that  one  test  could  apply  equally

th
Wel1  to  all  kinds  of  machine  operators,  for  the  work  of
°P e rators  is  as  variegated  as  the  work  of  clerks,  stenogra
 phers,  packers,  assemblers,  and  others.  If  special  tests
^ ere  needed  for  these  varieties  of  work,  it  seemed  logical
su ppose  that  machine  operators  of  different  kinds
^°uld  also  require  different  kinds  of  tests.  Therefore,
ai y  one  type  of  machine  was  chosen.  The  operation
a hy  chosen  was  that  of  hand-feed  dial  machines.  A  dial