SELECTING  GIRLS  AS  ASSEMBLERS

57

in  order  to  get  the  right  part  to  the  right  space  in  exactly
the  right  position.  In  one  case,  a  difference  of  one  thirtysecond
  of  an  inch  had  to  be  detected.  The  girl  who  can
detect  this  difference  at  a  glance  is  far  more  successful
than  the  girl  who  has  to  try  the  piece  out  first  in  one  position ­
  and  then  another  until  the  proper  fit  is  found.  In
order  to  detect  these  qualities,  a  test  for  the  perception  of
°dd  shapes  and  sizes  was  devised.  It  consists,  like  the
dexterity  tests  just  described,  of  a  board  with  pieces
cu t  out,  except  that  in  this  case  the  pieces  are  of  odd
shapes.  Some  pieces  are  quite  different  in  shape,  but
some,  almost  alike  in  shape,  differ  very  slightly  as  to
size.  When  the  test  is  given  the  pieces  are  dropped
into  the  cover  of  the  form  board  and  arranged  there  according ­
  to  a  predetermined  scheme.  Then  the  subject
ls  asked  to  size  each  piece  up  carefully  and  put  it  into  its
proper  space,  making  as  few  mistakes  as  possible.
It  is  very  interesting  to  watch  the  various  subjects  take
this  test.  Some  girls  see  at  a  glance  where  each  piece
belongs.  Others  have  not  the  least  conception  of  the  relation ­
  between  certain  shapes  and  certain  spaces,  but  aimlessly ­
  try  out  each  piece  at  one  opening  after  another
until,  by  chance,  the  right  space  is  hit  upon.
Besides  the  mental  qualities  just  described,  the  work
°I  assembling  requires  strong  hands.  In  order  to  determ
 ine  roughly  the  strength  of  the  hands,  a  grip-testing  instrument ­
  or  hand  dynamometer  is  used.  Each  girl  is
S'Ven  six  trials,  three  with  her  left  hand  and  three  with
ber  right.  The  number  of  pounds  registered  in  each  trial
ls  recorded  and  the  average  for  each  hand  constitutes  the
re cord.
The  conditions  under  which  this  experiment  was  conducted ­
  represent  a  departure  from  the  usual  procedure.