## Random things #8

Written on **18 March 2015, 10:28pm **

**Tagged with:** clocks, human behavior, internet, learning, maths, statistics

## 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

## About learning

*Learning isn’t done to you, it’s something you do*. You need to take responsibility of your education. There will always be a new technology to learn, but this is not that important. Is the **constant learning** that counts.

Andy Hunt – Pragmatic Thinking and Learning

We all tend to learn best by doing and teaching. Active learning is a much more effective way to learn than any other way.

It seems a bit strange, but it should really be no surprise that play is a powerful mechanism for learning. […] This simple process that comes natural to us all, but somehow gets “taught” out of us, is the simplest and purest way to learn.

John Sonmez – Soft Skills

## Random links:

– Brain bugs everywhere

– behavioral targeting – “behavioral targeting uses information collected from an individual’s web-browsing behavior to select advertisements to display”

– dark patterns are showing the ugly part of the Internet

– I started listening to podcasts

– I’m still not buying the iPhone 6

– It looks like **brogramming** is not how Barney Stinson would call *pair programming* 🙂

– The Stelton 851 is awesome. And look at the filename! Pure coincidence 🙂

*Written by*
**Dorin Moise**
(Published articles: 231)

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