Oneway ANOVA: Follow-up tests

Week 7

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Concepts

• Follow-up tests after a significant omnibus F-test
• conceptual review of Type-I errors
• how Type-I error rate is determined by \alpha used for deciding significance
• Type-II errors and statistical power
• multiple comparisons problem and Type-I error inflation
• corrections for multiple comparisons (Bonferroni, Tukey, Bonferroni-Holm)
• unbalanced designs (unequal n)

Required Readings

• Chapter 14—Comparing several means (one-way ANOVA) in Learning Statistics with R by Danielle Navarro (pdf version)
  • focus on sections: 14.5
  • also read section 16.9 on “planned comparisons”
  • read section 11.8 on “Effect size, sample size and power”
• Chapter 12—Thinking about answering questions with data in Answering questions with data by Matthew J. C. Crump, specifically the sections on effect-size and power

Additional supporting materials

• Chapter 7—ANOVA in Answering questions with data by Matthew J. C. Crump
• ANOVA R simulations of the null hypothesis by Matthew J. C. Crump