Regression with Categorical Explanatory Variables

When running a regression model with a categorical explanatory variable, a set of dummy variables are created to represent the possible levels of this categorical variable aside from the reference level that receives no dummy variable. A multiple regression model is fit. The intercept represents the expected response for the reference level while the remaining coefficients are the difference in expected response between the other levels and the reference level.

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Chapters:
00:00 Introduction
00:35 Using a categorical variable as an explanatory variable
01:24 Regression with a categorical variable
03:40 Multiple regression model with dummy variables
06:23 R code constructing dummy variables
07:05 Parameter Interpretation
08:49 Visual representation of multiple regression with dummy variables
09:33 Equivalence to a multiple group model
10:24 Summary


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