1. Stat 414 – Day 20

2. Last week – Random coefficients
Random intercepts: 1 + (1 | id)
Random slopes: 1 + large + (large | id)
Interaction with Level 2 grouping variable
Level 2 covariates: 1 + large + orch + large*orch…
Creates a cross-level interaction

3. Interactions
Random slopes – interaction with level 2 grouping variable
Interactions
Within level
Cross level – including Level 2 covariates to explain variation in intercepts, slopes

4. Example 5.2 IQ and mean IQ in text Coefficient of IQ_verb in a school:
meanIQ + random slope effect
A negative mean IQ means the effect of individual IQ on language test is much larger

5. Data

6. Data
Large performances
Small performances

7. Model
Large performances
Small performances

8. To Do
Submit HW 4
Next project report