Entropy is a fundamental concept in Data Science because it shows up all over the place - from Decision Trees, to similarity metrics, to state of the art dimension reduction algorithms. It's also surprisingly simple, but often poorly explained. Traditionally the equation is presented with the expectation that you memorize it without thoroughly understanding what it means and where it came from. This video takes a very different approach by showing you, step-by-step, where this simple equation comes from, making it easy to remember (and derive), understand and explain to your friends at parties.

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0:00 Awesome song and introduction
1:28 Introduction to surprise
4:34 Equation for surprise
6:09 Calculating surprise for a series of events
9:35 Entropy defined for a coin
10:45 Entropy is the expected value of surprise
11:41 The entropy equation
13:01 Entropy in action!!!

#StatQuest #Entropy