Building the model

As part of the model building process, first build a simple Poisson regression. A glm() runs quicker than glmer() and is easier to debug. For example, the Poisson regression might catch if you have non-integer data. Plus, the Poisson regression can provide intuition about the more complicated model.

If you run into any problems, follow the instructions to fix your data.

Last, build and save a repeated-measures Poisson regression.