# mlmhelpr

A package of helper functions for multilevel models fit using the `lme4`

package

## Authors

## Installation

To install the latest development version directly from Github, type:

install.packages(“remotes”)

remotes::install_github(“lrocconi/mlmhelpr”)

## Functions

`boot_se`

Compute bootstrap standard errors and confidence intervals for fixed effects

`center`

Automatically grand- or group-mean center variables and re-estimates the model

`design_effect`

Calculate the design effect to determine if multilevel modeling is needed

`hausman`

Perform a Hausman test to test for differences between random- and fixed-effects models (experimental)

`icc`

Calculate the intraclass correlation

`ncv_tests`

Computes three different Non-constant variance tests (experimental)

`plausible_values`

Compute the plausible value range for random effects

`r2_cor`

Calculate the squared correlation between the observed and predicted values

`r2_pve`

Compute the proportion of variance explained for each random effect in the model

`reliability`

Calculate reliability coefficients for random effects

`robust_se`

Computes robust standard errors for `lmer`

models

`taucov`

Calculate correlation between random intercepts and slopes