# More About Model Selection

Learn how to decide which specific model to use.

## We'll cover the following

## Introduction

How do we know if we should include some random effects in our model? One way is by using AIC to compare two models that differ only because one has random effects and the other doesn’t. For example, we can build a linear model like `lmm1`

, but that model doesn’t have any random effects. We’ll use `RxP.clean`

to facilitate a comparison with the `lmm1`

model here:

Get hands-on with 1200+ tech skills courses.