# How does "Random Sample" work?

Question asked by Phillip Wild on May 28, 2015
Latest reply on Sep 18, 2017 by Marisa Rybar

I've seen "Random Sample" in Flow steps when you use "Add Choice". But...is this self contained random samples, or is it reducing the amount of leads flowing through as it goes?

As an example:

Choice 1: If Random Sample is 33%, send email A

Choice 2: If Random Sample is 33%, send email B

Default: Send Email C

Would this work? Does the second random sample start afresh from the full amount of leads, or is it smart enough to remove anyone who qualified for Choice 1?

My theory is that it will remove as it goes, which means you would need to adjust the percentages. So if you started with 100 people:

* 33 people qualify for Email A and get that send. 67 remain.

* 33% * 67 = approx 23 people then qualify for Email B and get that send.

* The remaining 100 - (23 + 33) = 44 people will get Email C.

So if you wanted to get three splits of 33% each, the second choice should say 50%.

This is basically just a more difficult way to do an A/B test through that functionality, so I wouldn't necessarily use it like that - but I'd love to know 100% how the functionality works so I can think about how to use it.

Thanks, Phil