1. Psychology 202b Advanced Psychological Statistics, II March 8, 2011

2. Overview More power analysis for regression. Continuous interactions.

3. Power analysis for regression Last time, we focused on required N. “Post hoc” power analysis. Minimum detectable effect size.

4. Algebra of effect sizes

5. Continuous interactions How to code and interpret continuous interactions. The importance of centering.

6. Devices for understanding interactions +- one standard deviation. Using categorical representations.

7. Next time Review for the midterm exam. A study guide will be posted tonight. Come armed with questions.