Principal Component Analysis

In this post, we will learn about Principal Component Analysis (PCA) -- a popular dimensionality reduction technique in Machine Learning. Our goal is to form an intuitive understanding of PCA without going into all the mathematical details. At the time of writing this post, the population of the United States is roughly 325 million. You may think millions of people will have a million different ideas, opinions, and thoughts, after all, every person is unique. Let's say you select 20 top political questions in the United States and ask millions of people to answer these questions using a yes or a no.