ResultsStandardizeR: Calculate cohen's d, variance, and standard errors.

In setgree/ResultsStandardizeR: Some functions that Seth Green & John-Henry Pezzuto wrote to assist with a forthcoming meta-analysis

Description

ResutsStandardizeR Converts any of the following statistics into an estimate of Cohen's d s, variance, and standard error: difference in means, difference in differences, t-tests, F-tests, and regression coefficients into an estimated standard effect size and measure of uncertainty. The function requires an effect statistic, an estimate of the standard deviation of the dependent variable, an N for the control group, and an N for the treatment group. Note: t-tests, F-tests, and standardized regression coefficients do not require a standard deviation.

Usage

ResultsStandardizeR(
  eff_type,
  u_s_d,
  pop_sd,
  n_t,
  n_c,
  write_to_csv = NULL,
  append = NULL
)

Arguments

eff_type	Write the effect type you are converting. Current options are "d_i_d" (difference-in-differences), "d_i_m" (difference-in-means), "st_reg_coef" (standardized regression coefficient), "reg_coef" (regression coefficient), t_test" (t-test), and "f-test" (f-test). Note: you must include quotes.
u_s_d	Unstandardized effect size.
pop_sd	Estimate of the population standard deviation for the dependent variable. Not necessary if the effect size is "st_reg_coef" (assumed to be 1), "t_test" or "f_test."
n_t	Number of subjects in the treatment group.
n_c	Number of subjects in the control group.

Details

All calculations taken from Cooper, Hedges, and Valentine (2009)

Value

results_table is a dataframe that displays cohen's d, variance, and standard error.

See Also

Cooper, Hedges, and Valentine (2009), "The Handbook of Research Synthesis and Meta-Analysis, Second Edition", chapter 12.

Examples

```ResultsStandardizeR(eff_type = "reg_coef",
 u_s_d = .366, pop_sd = 1.074,
 n_t = 35, n_c = 1036)```
```ResultsStandardizeR(eff_type = "d_i_d" ,
 u_s_d = (111.1 - 92.7) - (102.9 - 99.4) ,
 ctrl_sd = 28.28, n_t = 15, n_c = 15)```

setgree/ResultsStandardizeR documentation built on June 2, 2020, 11:48 a.m.