1. 1 Joyful mood is a meritorious deed that cheers up people around you like the showering of cool spring breeze.

2. 2 Categorical Data Analysis Chapter 6: Building Logistic Regression Models

3. 3 Model Selection Stepwise/backward/forward selection SAS PROC LOGISTIC AIC criterion: AIC = -2(max. log likelihood - # of parameters) The smaller the AIC is, the better the model is

4. 4 Example: Crab data Visit Table 6.2 (p. 215)  Model symbols  Backward elimination (models 1-7)  AIC values  More advanced model selection (model 8) SAS example code: crab.sas

5. 5 Model Diagnostics Assessment of the overall goodness of fit: Deviance measures the amount of loss of information Residuals: Identify the lack of fit cells