how to estimate how different two sets are?

Hello,

I have the following problem. I have a group of samples. For simplicity lets say 10 samples s1 through s10. I randomly split them into two sets of equal size (both sets put together make up the whole group of samples). Lets for the sake of example and clarity make sets as following:

set 1: s1, s4, s6, s9 and s10

set 2: s2, s3, s5, s7 and s8.

Now I do it all over and create another selection of two equal sized random sets, for example:

set 1': s1, s3, s4, s8 and s10

set 2': s2, s5, s6, s7, and s9.

My question is how can I determine how different these two selections are? It might be easy to do visually when you have 10 samples, but I have about 50 samples and used 10 only to clearly explain my problem. Is there some kind of statistics I can calculate which would let me determine if my selections 1,2 and 1', 2' differ by more than just a couple of samples interchanged between the sets?

Thank you :)