ANCOVA - How to do it in R, interpretation

In this lecture, I explain the meaning of ANCOVA and interaction in ANCOVA. The diagnostic plots are discussed in greater detail here:    • Lecture: Model Diagnostics [see description]   When you use multiple linear regression (including ANCOVA), the question of which variables and/or interactions arises. For a more definitive discussion about model selection, see:    • Lecture: Model Selection   If you use multiple linear regression (including ANCOVA) for hypothesis testing (i.e. do my variables have a significant effect?), you should use a form of multiple testing correction:    • Mini Lecture: Multiple Testing   0:00 Introduction 1:28 Recap of simple linear regression 4:29 Simple linear regression in R 7:55 Multiple linear regression 10:57 Dummy variables (ANCOVA) 14:42 ANCOVA in R 18:00 ANCOVA in R: Interpreting the output 19:23 ANCOVA in R: Changing the intercept (relevel) 22:07 Interaction 24:32 Interaction in R 25:09 Interaction in R: Interpreting the output 28:08 Comparing a model with and without interaction 31:30 Summary: Interaction 32:31 Summary: All models discussed so far 33:24 ANCOVA can be more powerful than ANOVA