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102  EMPLOYMENT  PSYCHOLOGY
sufficient  ground  upon  which  to  make  very  extensive  deductions. ­
  In  fact,  the  psychologist  who  bases  conclusions
with  regard  to  the  significance  of  tests  upon  a  study  of
less  than  twenty  subjects  at  the  least  feels  that  he  is
resting  on  very  precarious  ground  indeed.