cohens_d: Cohen's d

In dgromer/psymisc: Miscellaneous functions for psychologists

Description

Calculate Cohen's d from raw data or a call to t_test/t.test.

Usage

cohens_d(...)

## Default S3 method:
cohens_d(x, y = NULL, paired = FALSE, corr = c("none",
  "hedges_g", "glass_delta"), na.rm = FALSE, ...)

## S3 method for class 'data.frame'
cohens_d(data, dv, iv, paired = FALSE, corr = c("none",
  "hedges_g", "glass_delta"), na.rm = FALSE, ...)

## S3 method for class 'formula'
cohens_d(formula, data, paired = FALSE, corr = c("none",
  "hedges_g", "glass_delta"), na.rm = FALSE, ...)

## S3 method for class 'htest'
cohens_d(ttest, corr = c("none", "hedges_g", "glass_delta"),
  ...)

Arguments

...	Further arguments passed to methods.
x	a (non-empty) numeric vector of data values.
y	an optional (non-empty) numeric vector of data values.
paired	a logical indicating whether Cohen's d should be calculated for a paired sample or two independent samples (default). Ignored when calculating Cohen's for one sample.
corr	character specifying the correction applied to calculation of the effect size: "none" (default) returns Cohen's d, "hedges_g" applies Hedges correction and "glass_delta" calculates Glass' Δ (uses the standard deviation of the second group).
na.rm	logical. Should missing values be removed?
data	a data frame containing either the variables in the formula formula or the variables specified by dv and iv.
dv	character indicating the name of the column in data for the dependent variable
iv	character indicating the name of the column in data for the independent variable
formula	a formula of the form lhs ~ rhs where lhs is a numeric variable giving the data values (dependent variable) and rhs a factor with two levels giving the corresponding groups (independent variable).
ttest	an object of class htest (a call to either t_test (preferred) or t.test).

References

Lakens, D. (2013). Calculating and reporting effect sizes to facilitate cumulative science: a practical primer for t-tests and ANOVAs. Frontiers in Psychology, 4, 863. doi:10.3389/fpsyg.2013.00863

Examples

cohens_d(c(10, 15, 11, 14, 17), c(22, 18, 23, 25, 20))

# Methods when working with data frames
cohens_d(hquest, dv = sens_seek, iv = group)
# or
cohens_d(hquest, dv = "sens_seek", iv = "group")
# formula interface
cohens_d(sens_seek ~ group, hquest)

# Or pass a call to t_test or t.test
cohens_d(t_test(sens_seek ~ group, hquest))

dgromer/psymisc documentation built on May 15, 2019, 7:22 a.m.