Chapter 3 Why choose mixed models?

Biological and ecological data are often messy. Most of the time there is an inherent structure to data (i.e. single observations are not always independent), relationships between variables of interest might differ depending on grouping factors like species, and more often than not sample sizes are low, making it difficult to fit models that require many parameters to be estimated.

Linear mixed effects models (LMM) were developed to deal with these issues. They can be applied to a great number of ecological questions and take many different forms. In this workshop we will use a simple question-based approach to learn the basics of how LMM operate and how to fit them.