# Linear Regression

## Linear Models

So far we’ve finished the main materials of this course - estimation and hypothesis testing. The starting point of all the statistical analyses is really modeling. In other words, we assume that our data are generated by some random mechanism, specifically we’ve been focusing on i.i.d. samples from a fixed population distribution. Although this assumption can be regarded reasonable for many applications, in practice there are other scenarios where this doesn’t make sense, e.