This enable the decision  maker to select the most appropriate course of  action. This  needs more care  and efforts. If  validates or verifies the  expected outcomes  of each  hypothesis. Here greatest  volume and intensity of data are  likely  to be  gathered. Sometimes uncertain conditions may force the decision maker  to use  his intuition and  judgment  but in  general  major  decisions  are always based  on convulsive  research.
The  utility  and performance of decision  with  regard to  the solution  of a problem can  be ascertained by  means  of performance monitoring research. It  reports the changes in operational  results  that appears  appropriate to the action  and also  ascertains whether the conditions under  which the action was  taken have turned out to  be significantly differently  from those  when the  action was  selected.