Sentence: the apparent overall shortened RT was mainly due to the shortening of personnel response time ( PRT ) and the time needed to draft a new questionnaire that incurred as personnel-system interface ( PSI ) ; PRT dropped from a fluctuating range of 9.8 ,28.8 days in the first four months to ,10 days in the following months and remained low till 2008 ( 0.8861.52 days ). 
 Section: method