infer_ts_ind_ttest: Two Independent Sample t Test

In inferr: Inferential Statistics

Description

infer_ts_ind_ttest compares the means of two independent groups in order to determine whether there is statistical evidence that the associated population means are significantly different.

Usage

infer_ts_ind_ttest(
  data,
  x,
  y,
  confint = 0.95,
  alternative = c("both", "less", "greater", "all"),
  ...
)

Arguments

data	a data frame
x	factor; a column in data
y	numeric; a column in data
confint	confidence level
alternative	a character string specifying the alternative hypothesis, must be one of "both" (default), "greater", "less" or "all". You can specify just the initial letter
...	additional arguments passed to or from other methods

Value

infer_ts_ind_ttest returns an object of class "infer_ts_ind_ttest". An object of class "infer_ts_ind_ttest" is a list containing the following components:

levels	levels of x
obs	number of observations of y for each level of x
n	total number of observations
mean	mean of y for each level of x
sd	standard deviation of y for each level of x
se	estimate of standard error of y for each level of x
lower	lower limit for the mean of y for each level of x
upper	upper limit for the mean of y for each level of x
combined	a data frame; mean, standard deviation, standard error and confidence limit of mean of y
mean_diff	difference in mean of y for the two groups of x
se_dif	estimate of the standard error for difference in mean of y for the two groups of x
sd_dif	degrees of freedom
conf_diff	confidence interval for mean_diff
df_pooled	degrees of freedom for the pooled method
df_satterthwaite	degrees of freedom for the Satterthwaite method
t_pooled	t statistic for the pooled method
t_satterthwaite	t statistic for the Satterthwaite method
sig_pooled	two-sided p-value for the pooled method
sig_pooled_l	lower one-sided p-value for the pooled method
sig_pooled_u	upper one-sided p-value for the pooled method
sig	two-sided p-value for the Satterthwaite method
sig_l	lower one-sided p-value for the Satterthwaite method
sig_u	upper one-sided p-value for the Satterthwaite method
num_df	numerator degrees of freedom for folded f test
den_df	denominator degrees of freedom for folded f test
f	f value for the equality of variances test
f_sig	p-value for the folded f test
var_y	name of y
confint	confidence level
alternative	alternative hypothesis

Deprecated Function

ind_ttest() has been deprecated. Instead use infer_ts_ind_ttest().

References

Sheskin, D. J. 2007. Handbook of Parametric and Nonparametric Statistical Procedures, 4th edition. : Chapman & Hall/CRC.

See Also

t.test

Examples

# lower tail
infer_ts_ind_ttest(hsb, female, write, alternative = 'less')

# upper tail
infer_ts_ind_ttest(hsb, female, write, alternative = 'greater')

# both tails
infer_ts_ind_ttest(hsb, female, write, alternative = 'both')

# all tails
infer_ts_ind_ttest(hsb, female, write, alternative = 'all')

inferr documentation built on May 29, 2021, 1:07 a.m.