Transcript Statistics 400 - Simon Fraser University

Statistics 350
Lecture 28
Today
• Last Day: Section 9.6 on Model Validation
• Today: Leverage Plots
Leverage Plots (Partial Regression Plots)
• Relationships seen in plots using any one explanatory variable may be
obscured by the effects of other explanatory variables (same thing happens in
tests)
• Correlations between explanatory variables make it difficult to separate out
effects on the response due to different explanatory variables
Leverage Plots (Partial Regression Plots)
• A Partial Regression (Leverage) Plot (PRLP) is an attempt to look at
individual relationships between the response and explanatory variables
without interfering effects from other explanatory variables
Leverage Plots (Partial Regression Plots)
•
Idea: to isolate the effect of a particular Xj from the rest of the explanatory
variables
•
Steps:
1.
2.
3.
Leverage Plots (Partial Regression Plots)
•
Idea: to isolate the effect of a particular Xj from the rest of the explanatory
variables
•
Steps:
1.
2.
3.
Leverage Plots (Partial Regression Plots)
•
Notes:
Leverage Plots (Partial Regression Plots)
•
Notes: