The first step in fitting any linear models should be exploratory graphing with the raw data. In many cases, this step will provide preliminary answers to the hypotheses and will provide a general idea of the effect sizes for the predictors. Sometimes, descriptive graphs will not provide the whole picture, in particular when the response is binary or with multiple continuous predictors. In these cases, it useful to plot the model predictions in order to fully understand the model.
This workshop will cover both how to create descriptive graphs and model-prediction graphs for a range of linear and logistic models. This workshop assumes familiarity with linear models (regression and anova) as well as logistic regression.
Methods will be demonstrated in a hands-on fashion using R, with the help of the ggplot2 and emmeans packages.
Downloading R and R Studio:
If you intend follow along with the R coding during the workshop, please make sure that you have the latest version of R and RStudio installed.
First, you will need to download and install R. R can be downloaded at: https://cran.r-project.org/.
Next you will need to download and install RStudio. We will use RStudio in this workshop. You can download RStudio at:
https://rstudio.com/products/rstudio/download/#download.