Random things #8

Written on 18 March 2015, 10:28pm

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A/B vs Multivariate Testing

A/B testing: two versions (A and B) are compared, which are identical except for one variation that might affect a user’s behavior. Total number of variations: 2. More
Multivariate testing: multiple variables are modified for testing a hypothesis. The goal of multivariate testing is to determine which combination of variations performs the best out of all of the possible combinations. `[Total # of Variations] = [# of Variations on Element A] X [# of Variations on Element B] ...` More

Permutations, Arrangements, Combinations

Given a set of n elements (ex – for n=3, the set is A, B, C)
Permutations: each ordered set of n elements `P(n) = n! `
In our example with n=3, P(3)=3!=6: АВС, АСВ, ВАС, ВСА, САВ, СВА
Arrangements: each ordered set of k elements `A(n,k) = n! / (n-k)!`
In our example with n=3, ordered pairs of 2, A(3,2)=3!/(3-2)!=6: AB, BA, AC, CA, BC, CB
Combinations: each unordered set of k elements `C(n,k) = n! / k! (n-k)!`
In our example with n=3, un-ordered pairs of 2, C(3,2)=3!/2!*1!=3: AB, AC, BC
And the relationship between P, A, C: `C=A/P`
Remember that for the permutations you don’t need a k! More