Format statistical results in APA style

The apa function provides a convenient way to format statistical results according to American Psychological Association (APA) style guidelines. It dispatches to various S3 methods depending on the class of the input object.

Usage

apa(obj, ...)

Arguments

obj

An object to format in APA style

...

Additional arguments passed to specific methods

Value

The result of the method for obj: usually a character vector of APA-formatted statistical results. Regression methods can return a data.frame of coefficient summaries, and ANOVA methods can return a data.frame with formatted text appended when requested. See each method's documentation for its columns and selection options.

Details

This function supports various statistical objects directly:

• apa.ttest for stats::t.test and apa.r for stats::cor.test (both with class htest)

• apa.aov for stats::aov, apa.anova for car::Anova, and apa.afex_aov for afex::aov_ez, afex::aov_car, or afex::aov_4

• apa.glm for stats::glm, stats::lm, lme4::lmer, lme4::glmer, and lmerTest::lmer; apa.lmert remains available for summary objects from lmerTest::lmer

• apa.brmsfit for brms::brm and apa.BFBayesFactor for BayesFactor::anovaBF

• apa.chisq.test for stats::chisq.test

• apa.dip.test for diptest::dip.test

• apa.roc.test for pROC::roc.test

In addition, there are standalone utility functions for formatting:

• apa_mean_sd: Format means and standard deviations

• apa_mean_conf: Format means and confidence intervals

• apa_binom_mean_conf: Format binomial means and confidence intervals

• apa_mean_and_t: Compare means with t-tests and format results

• table_mean_conf: Get formatted means and CIs (for tables)

• table_mean_conf_by: Get formatted means and CIs by group (for tables)

Examples

# t-test example
t_res <- t.test(rnorm(30), rnorm(30, 0.5))
apa(t_res)
#> [1] "_t_(51.1) = -3.32, _p_ = .002"

# Correlation example
cor_res <- cor.test(mtcars$mpg, mtcars$wt)
apa(cor_res)
#> [1] "_r_(30) = -0.87, _p_ < .001"