| The DTREE Procedure | 
The MODIFY statement is used to change either the type of a stage or 
 the reward from an outcome.  If MODIFY outcome-name REWARD 
 new-value is given where the outcome-name is 
 an outcome specified in the 
 STAGEIN= data set, and new-value 
 is a numeric value, then 
 the reward of the outcome named 
 outcome-name is changed to new-value.
 
If MODIFY stage-name TYPE is given where stage-name is a 
 stage name specified in the STAGEIN= data set, 
 then the type of the stage 
 named stage-name is changed to 'DECISION' if its current type 
 is 'CHANCE' and is changed to 'CHANCE' if its current type 
 is 'DECISION'.  You cannot 
 change the type of an 'END' stage.  The change of the type of 
 a stage from 'CHANCE' to 'DECISION' can help 
 the decision-maker learn how much improvement 
 can be expected if he or she could pick which of the future (or unknown) 
 outcomes would occur. 
 However, if you want to change the type of 
 a stage from 'DECISION' to 'CHANCE', the procedure 
 is not able to 
 determine the probabilities for its outcomes unless you specify them 
 in the PROBIN= data set.
 
Copyright © 2008 by SAS Institute Inc., Cary, NC, USA. All rights reserved.