apa_print.merMod: Typeset Statistical Results from Hierarchical GLM

Description

These methods take objects from various R functions that calculate hierarchical (generalized) linear models to create formatted character strings to report the results in accordance with APA manuscript guidelines.

Usage

# S3 method for merMod
apa_print(
  x,
  effects = "fixed",
  conf.int = 0.95,
  in_paren = FALSE,
  est_name = NULL,
  ...
)
# S3 method for mixed
apa_print(x, ...)

Value

apa_print()-methods return a named list of class apa_results containing the following elements:

estimate: One or more character strings giving point estimates, confidence intervals, and confidence level. A single string is returned in a vector; multiple strings are returned as a named list. If no estimate is available the element is NULL.
statistic: One or more character strings giving the test statistic, parameters (e.g., degrees of freedom), and p-value. A single string is returned in a vector; multiple strings are returned as a named list. If no estimate is available the element is NULL.
full_result: One or more character strings comprised `estimate` and `statistic`. A single string is returned in a vector; multiple strings are returned as a named list.
table: A data.frame of class apa_results_table that contains all elements of estimate and statistics. This table can be passed to apa_table() for reporting.

Column names in apa_results_table are standardized following the broom glossary (e.g., term, estimate

conf.int, statistic, df, df.residual, p.value). Additionally, each column is labelled (e.g., $\hat{\eta}^2_G$ or $t$ ) using the tinylabels package and these labels are used as column names when an apa_results_table is passed to apa_table().

Arguments

x: A fitted hierarchical (generalized) linear model, either from lme4::lmer(), lmerTest::lmer(), afex::mixed(), or lme4::glmer().
effects: Character. Determines which information is returned. Currently, only fixed-effects terms ("fixed") are supported.
conf.int: Numeric specifying the required confidence level or a named list specifying additional arguments that are passed to lme4::confint.merMod(), see details.
in_paren: Logical. Whether the formatted string is to be reported in parentheses. If TRUE, parentheses in the formatted string (e.g., those enclosing degrees of freedom) are replaced with brackets.
est_name: An optional character. The label to be used for fixed-effects coefficients.
...: Further arguments that may be passed to apa_num to format estimates (i.e., columns estimate and conf.int).

Details

Confidence intervals are calculated by calling lme4::confint.merMod(). By default, Wald confidence intervals are calculated, but this may change in the future.

Examples

Run this code

# \donttest{
  # Fit a linear mixed model using the lme4 package
  # or the lmerTest package (if dfs and p values are desired)
  library(lmerTest)
  fm1 <- lmer(Reaction ~ Days + (Days | Subject), sleepstudy)
  # Format statistics for fixed-effects terms (the default)
  apa_print(fm1)
# }