APPENDIX

399

rate  into  two  packs.  On  this  side  of  the  board  where  you
see  the  ‘  O  ’  (pointing  to  left  side  of  a  12"  x  12"’cardboard
with  an  ‘O’  in  the  upper  left  hand  corner)  put  all  cards
which  have  an  ‘  O  ’  on  them.  On  the  other  side,  put  those
that  do  not  have  an  *  O  Try  it  with  this  pack  (handing
subject  the  sample  pack  of  six  cards,  three  with  and  three
without  an  ‘  O  ’).  Now  do  it  with  this  whole  pack  quickly
and  carefully.  Ready?  Start.”  (Press  stop-watch  at
the  word  ‘start  ’  and  again  when  subject  is  finished.)
Record:
Turn  cards  face  down  and  sort  back  into  original  order
according  to  numbers  on  the  back  of  each  card,  counting
mistakes  in  the  process.  Record  as  follows:  number  of
test,  seconds  taken,  number  of  mistakes  made.  For  example, ­
  2;  35  secs.,  2  E.
Rating:
Read  following  section  on  rating.  All  tests  are  rated  according ­
  to  one  of  two  formulae.  In  this  one  we  apply
formula  II.  The  point  of  reference  is  sorting  the  50  cards
in  25  seconds.  RU,  or  the  total  number  of  units  in  the
test  is  50  (cards).  Ru,  or  the  reference  time  per  unit  is
.7,  i.  e.,  35  (seconds)  -f-  50  (units).
E,  the  number  of  errors,  to  be  counted  double.  T,  the
time.  Applying  formula  II  to  the  above  sample  record,

(  Ru  X  RU  —  2  E  )
T

=  rating,

•7  X  (50  ~  4)
35

=  .92

C.  RATING
Because  of  the  multiplicity  of  varieties  of  tests  and  ways
of  giving  them,  much  confusion  has  arisen  over  the  methods  of
rating.  Some  tests  are  rated  according  to  the  amount  done  in
a  given  time;  others,  according  to  the  time  taken  to  complete
the  entire  test  others,  according  to  the  number  of  correct  and
false  moves;  etc.,  etc.  Because  of  this  variety  and  subsequent