I cumulated the single sys_pagetime_X values on respondent level and compared the sum with sys_SumPageTimes. Somehow those figures have a discrepancy, sometimes low sometimes pretty high (several minutes of difference).
What can be a reason for the discrepancy, and which would be more accurate? sys_SumPageTimes or the sum of all individual page times?
At the end of the day I need the actual survey time per respondent. From other threads I found out that sys_SumPageTimes is the metric I am looking for (not sys_ElapsedTime), so I wanted to validate sys_SumPageTimes by cumulating the single sys_pagetime_X values.