Week 11: Brief intro to power analysis and Bayesian statistics

These lectures will represent a brief introduction to the topics of power analysis and Bayesian statistics. There is simply no time to go into these in any sort of detail, so the objective today will be just to familiarize yourself with the basic logic of these techniques, and where to go to learn more.

Lecture Topics

• Power analysis:
  • What is it?
  • Why do it?
  • How can you do it with GLMMs?
• Bayesian statistics:
  • What is it?

Resources

Bayesian stats:

• JAGS - Just Another Gibbs Sampler
• Ellison, A. M. (2004). Bayesian inference in ecology. Ecology letters, 7(6), 509-520.
• Getting started with JAGs in R
• Using JAGS in R with the rjags package
• Eguchi, T. (2008). An introduction to Bayesian statistics without using equations. Marine Turtle Newsletter, 122, 1-5.
• Picking priors: Choy, S. L., O’Leary, R., & Mengersen, K. (2009). Elicitation by design in ecology: using expert opinion to inform priors for Bayesian statistical models. Ecology, 90(1), 265-277.

Power Analysis:

• Documentation for the pwr package: https://www.rdocumentation.org/packages/pwr/versions/1.2-0/
• Don’t do post-hoc power analyses: Hoenig, J.M and D.M. Heisey. 2001. The abuse of power: The pervasive fallacy of power calculations for data analysis. The American Statistician 55, 19-24.
• Power analysis for GLMMs: Johnson, P. C., Barry, S. J., Ferguson, H. M., & Müller, P. (2015). Power analysis for generalized linear mixed models in ecology and evolution. Methods in ecology and evolution, 6(2), 133-142.
• An R package, implementing GLMM power analysis: Green, P., & MacLeod, C. J. (2016). SIMR: an R package for power analysis of generalized linear mixed models by simulation. Methods in Ecology and Evolution, 7(4), 493-498.

Files

Just a single R script today: FISH6003_Week11-PowerAnalysis.R

Slides

Slides available on Speakerdeck