Residuals

Actual – Predicted = Error Predicted “Residual” in statistics is the same as “error” Residual = Actual y – Predicted y Source: http://www.studyworksonline.com, 8/13/03 Actual Actual – Predicted = Error Predicted

“Residual” in statistics is the same as “error” Residual = Actual y – Predicted y Source: http://www.studyworksonline.com, 8/13/03 Positive residual

“Residual” in statistics is the same as “error” Residual = Actual y – Predicted y Source: http://www.studyworksonline.com, 8/13/03 Negative residual

Residual plot

1-1 correspondence between every point on the scatterplot and the corresponding point on the residual plot

Residuals No Pattern Clear Pattern  Appropriate Model Concave up or down No Pattern Clear Pattern Increasing or decreasing Too high or low  Appropriate Model  Inappropriate Model Small Residuals Large Residuals  Appropriate Model  Appropriate Model, But Not Very Useful

Pattern – Clear concave down pattern Magnitude – Small residuals Conclusion - Not an appropriate model

Pattern – No clear pattern Magnitude – Fairly large residuals Conclusion - Appropriate , but not very useful model

Pattern – No clear pattern Magnitude – Small residuals Conclusion - Very appropriate model

Pattern – Clear decreasing pattern Magnitude – Small residuals Conclusion - Not an appropriate model

Pattern – Clear pattern, residuals too low Magnitude – Small residuals Conclusion - Not an appropriate model

Residuals