Mixed-Effects Models in R

This tutorial introduces mixed-effects models in R, covering the rationale for random effects, the distinction between fixed and random effects, model fitting with lme4, contrast coding, and the interpretation of model output. It includes worked examples using linguistic data and is aimed at researchers in linguistics and the humanities who work with hierarchical or repeated-measures data. This tutorial is part of the Language Technology and Data Analysis Laboratory (LADAL), a free, open-access research infrastructure at the University of Queensland. LADAL provides tutorials, tools, and courses for researchers working with language data. All materials are freely available at https://ladal.edu.au and are part of the Language Data Commons of Australia (LDaCA), funded by ARDC and NCRIS.