Formula to determine sample size

[taylortoowen]

Hi everyone,

I am trying to come up with a calculated metric that will estimate the necessary sample size to draw meaningful conclusions from an A|B test. I have been able to do this with binary metrics, like conversion, but I want to study other KPIs in the same way. Does anyone know a way to estimate minimum sample size for something none-binary, like revenue per visitor, or average order value?

I know that adobe provides a test calculator for this sort of this, Adobe Target Sample Size Calculator, but is there a way to do this with a calculated metric so that I can track my progress in real time in workspace?

Thanks,

Taylor

[hk17541]

There are multiple methodologies out there - if you are trying to identify the formula for sample size calculator which Adobe uses please consider this:

x : Baseline Conversion Rate (control offer)

y: MDE

z1: Z score of Confidence Level

z2: Z score of Statistical Power

=2*((x*(1-x)+(1+y)*x*(1-(1+y)*x))/2)*(z1+z2)^2/(x-x*(1+y))^2