Let’s use the knowledge you took from Marketplace Mechanics, and dive deep into the data. The data is the most important thing to quantitative analysis. Without good data, you don’t have good predictions. That is sometimes referred to as the garbage in, garbage out principle. That is the quality of your data directly impacts the quality of your predictions, no matter what model you use. In this lesson, we’ll talk about a few common data sets that you’ll use and the difficulty with working with that data.