Day 14: random effects, choosing modelsΒΆ

5 / 29 / 2015



  • Recall t and F tests: what are they doing exactly. Where does my variability come from?
    • example within run (from previous course)
    • example random effect (between subjects).
  • Wait a second: What is a model exactly ?
  • I am choosing a very wrong model: Consequences on the results of t/F tests.
  • How do I know my model is - is not very wrong? the good, the bad, the ugly (reverse order)
    • the ugly: p-hacking. Let’s try it.
    • the bad: use R2.
    • the good: model validation
  • Model validation: Principle. Example of “random effect” model testing the effect of “grumpiness”.