296  EMPLOYMENT  PSYCHOLOGY
his  selections,  and  discover  whether  or  not  they  are  successful; ­
  second,  a  method  which  will  guide  the  worker’s
superiors  in  determining  when  a  worker  has  been  successful ­
  and  when  he  has  not;  in  other  words,  a  standard  method
by  which  to  determine  retention  as  well  as  selection.