# Week 8 — Regression

In this week, we are learning about linear regression with StatsModels. All the examples will use the StatsModels OLS (ordinary least squares) model, generally with the formula interface.

Activities:

- Introducing Regression
- Statistical Modeling
- Single Regression
- Prediction and Inference
- Week 8 Quiz
- Categorical Predictors
- Testing Assumptions
- Regression Model Assumptions
- Multiple Regression
- Measuring Prediction Accuracy
- Instances and Sampling
- Supporting Notebook
- StatsModels Examples and User Guide
- Bootstrapping Linear Regression
- Assignment 4

## Introducing Regression

## Statistical Modeling

### Resources

## Single Regression

In this video, I introduce single-variable regression.

Slide Clarification

On slide 6, where I show the slope, intercept, and variance in a model, I have extended the plot to include 0 at the left end of the *x*-axis.
This is to highlight the meaning of the intercept. It is important to note that the intercept is where the line **crosses zero**, not where it crosses the left Y-axis.

Also, when discussing this slide, I am imprecise but make it sound like the unexplained variance is the remainder after *projecting* the data onto the line.
It is the variance remaining after *subtracting* the line.
I am preparing a video for Week 9 that will provide more clarity on this relationship.

## Prediction and Inference

## Week 8 Quiz

Complete the Week 8 quiz in Blackboard.

## Categorical Predictors

## Testing Assumptions

## Regression Model Assumptions

Read Regression Model Assumptions from JMP.

## Multiple Regression

## Measuring Prediction Accuracy

## Instances and Sampling

## Supporting Notebook

- Regression notebook with code supporting the Penguin examples
- I have added the regression code to the correlation notebook to support the movie examples

## StatsModels Examples and User Guide

The following StatsModels pages document its OLS model:

## Bootstrapping Linear Regression

Read Bootstrapping for Linear Regression.

## Assignment 4

Assignment 4 is due **October 25, 2020**.