Complete factorial designs


  • Benefits of factorial designs
  • Interactions
  • Simple, marginal and interaction contrasts

Learning objectives

At the end of the session, students should be capable of

  • listing the benefits of factorial designs
  • interpreting an interaction plot and being aware of it’s limitation
  • interpreting model effects in sum-to-zero parametrization
  • reporting results from a two-way analysis of variance
  • determining whether or not simple or main effects are most suitable


Complementary readings

  • Chapter 7 of Maxwell et al. (2017).
  • Chapters 10-13 of Keppel & Wickens (2004).


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Keppel, G., & Wickens, T. D. (2004). Design and analysis: A researcher’s handbook. Pearson Prentice Hall.
Maxwell, S. E., Delaney, H. D., & Kelley, K. (2017). Designing experiments and analyzing data: A model comparison perspective (3rd ed.). routledge.
Meier, L. (2022). ANOVA and mixed models: A short introduction using R (Chapman & Hall/CRC, Eds.).