# Difference between STDEV & STDEVP • ### Question

• Can somebody please compare these 2 functions for me and explain with an example?

Thank You

Tuesday, April 11, 2006 4:59 PM

• You can find detailed description here (the second article has an example):

http://www.beyondtechnology.com/tips016.shtml

Quote:

• STDEV is used when the group of numbers being evaluated are only a partial sampling of the whole population. The denominator for dividing the sum of squared deviations is N-1, where N is the number of observations ( a count of items in the data set ). Technically, subtracting the 1 is referred to as "non-biased."

• STDEVP is used when the group of numbers being evaluated is complete - it's the entire population of values. In this case, the 1 is NOT subtracted and the denominator for dividing the sum of squared deviations is simply N itself, the number of observations ( a count of items in the data set ). Technically, this is referred to as "biased." Remembering that the P in STDEVP stands for "population" may be helpful. Since the data set is not a mere sample, but constituted of ALL the actual values, this standard deviation function can return a more precise result.

Tuesday, April 11, 2006 9:25 PM