# Abstract

This workshop will give a short introduction to mixed-effects models for
longitudinal data. We will look at data sets where data was collected for
subjects over several time points. The first part will be a basic introduction
of the concept of random effects and how they extend linear regression. This is
meant to get everybody on the same page and introduce some notation. We will fit
the models together in R using the lme4 package. In the second part, we will
extend the models into growth curve models to model time trends within and
between subjects. Special focus will be on parameter interpretation and what
should be kept in mind when fitting and interpreting growth curve models. This
course is suited for novices to mixed-effects models who want to understand the
basic concepts, but also for people with a bit more expertise who want to dig
into more details and deepen their understanding of parameter interpretation.

# Instructor

Dr. Nora Wickelmaier, statistics consultant at the Leibniz-Institut für
Wissensmedien (IWM), Tübingen

# Prerequisites

Participants will need to have installed:

* a current R version (https://cran.r-project.org/)
* an IDE for R (like RStudio or VSCode) or a text editor with syntax
  highlighting (like Vim or Notepad++)
* the R package lme4 (https://cran.r-project.org/package=lme4)

