Week 5

Day 1

Today

In Class Discussion Questions for Fieberg, Ch. 8 and Tredennick et al. 2021

• Summarize exploration, inference/explain, and prediction (Table 8.1) or Table 2

• What is stepwise selection? How does it perform?

• Why fit only one model? Drawbacks? How to decide on how many variables?

• What is AIC?

• What is Regularization using penalization?

• “Model selection is the Black Hole of Statistics”. What do you think?

• Covariate selection vs. model selection?

In-Class Group Questions

Variable Combinations

Assigned

• Background Reading (not required):
  • Gelman and Hill Ch. 11 and 12.

Day 2 (lab)

Today

• Lecture: Hierarchical Models

• Downloads: Files

• Install R packages:

# CRAN packages
install.packages(c("glmmTMB","broom.mixed","lme4"))

Assigned

• Kery and Kellner Ch. 2, sections 2.7-2.10.