R Tutorial: A first taste of Bayes

Want to learn more? Take the full course at https://learn.datacamp.com/courses/fundamentals-of-bayesian-data-analysis-in-r at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- Hi and welcome to this course on the fundamentals of Bayesian data analysis using R. And here's me, Rasmus Bååth, Data scientists and Bayesian enthusiast. I'll be your guide on your journey through this course. Let's get started! In 1941 the British made a breakthrough in the war against Nazi Germany. During the beginning of the war, the German forces had been using a purpose-built typewriter, the Enigma machine, to encrypt military communication. But in 1941 a British team spearheaded by computer scientist Alan Turing finally designed a method that could decrypt German communication, and needless to say, this gave the allied powers a huge advantage in war. The reason I start out a course on Bayesian data analysis with a story from the second world war is that a key to Alan Turing's success in cracking the Enigma code was his use of Bayesian methods. At the time, Bayesian methods were not widely used but nowadays they are used in everything from AB-testing and statistical modeling to machine learning and robotics. In a nutshell, what is Bayesian inference? Bayesian inference is a method for figuring out unknown or unobservable quantities given known facts. There are other inference methods for this, but what makes Bayesian inference Bayesian is that it uses probability to describe the uncertainty over what the values of the unknown quantities could be. In the case of the Enigma Machine, the unknown quantity Alan Turing wanted to figure out was the configuration of these three wheels. The person encrypting the message selected these wheels from a pool of eight different wheels and their position defined how messages were encrypted. But if you're not the person who encrypted the message you don't know which wheels were used and w