Bias Diagnostic for Linear Mixed Models

Provides a function to perform bias diagnostics on linear mixed models fitted with lmer() from the 'lme4' package. Compares an internal random-effects alignment diagnostic with a fitted permutation reference distribution, following Karl and Zimmerman (2021) . Conditional response-refit simulations separately record random-effects alignment and residual-weight contributions to estimation error. Karl and Zimmerman (2020) provide R code for implementing the test using 'mvglmmRank' output. Development and review were assisted by 'GPT o1-preview', 'GPT 5 Pro', and 'GPT6 Astra'; the author is responsible for the code and its interpretation.