Difference on the calculation for standard deviation in Quicksight

Q&A
,
1

There are a few options for calculating standard deviation in Quicksight, however, I do not fullyunderstand the difference between them:

  • stdev v.s. stdevp: the formular for both caculation is xxxx(measure, [group-by level]), so what is the difference between the two functions? What does the additional p stand for here?
  • stdevIf v.s. stdevpIf
  • stdevOver v.s. stdevpOver
2

Hi @yuchen1,
The ‘p’ stands for population. In the articles that you linked, you can see in the explanation section that ‘stdev’ calculates the standard deviation of the set of numbers whereas a ‘stdevp’ calculates the population standard deviation of the set of numbers.
The same goes for the if and over functions as well.

Let me know if you have any additional questions!

3

Thanks for replying Brett!

If i understand it correct, population standard deviation(stdevp) covers all the values in a data set. Is stdev the sample standard deviation? I tried both calculation on my dataset, and the results are the same.

4

Hi @yuchen1,
Correct, stdevp covers all values whereas stdev uses a sample.