How to Extract Reference Levels and Calculate Effect Sizes for Fixed Factors in Linear Mixed Models

Understanding and Addressing the "Number of Levels" Error in Linear Mixed-Effects Models

Extracting Standard Errors of Variance Components from GLMMadaptive: A Comprehensive Guide

Testing All Possible Combinations of Fixed Effects in Linear Mixed Models: A Comparative Approach

Error 'derivs is larger than length of x' in B-Splines Used with Linear Mixed-Effects Models (lmer)