Estimate Means Difference

Provides the mean difference, standard error, and confidence interval of the difference.

Usage

# S3 method for data.frame
estimateMeansDifference(frame, conf.level=.95, ...)

# S3 method for formula
estimateMeansDifference(formula, conf.level=.95, ...)

# S3 method for wsm
estimateMeansDifference(moments, corrs, conf.level=.95, ...)

# S3 method for bsm
estimateMeansDifference(moments, conf.level=.95, ...)

Arguments

frame

a set of (non-empty) numeric vectors of data values

formula

a formula of the form lhs ~ rhs where lhs is a numeric variable giving the data values and rhs a factor giving the corresponding groups

moments

a matrix/frame of descriptive/summary statistics

corrs

a matrix/frame of correlations among the measures

conf.level

confidence level of the interval

Details

This function compares two groups or variables. As such, the supplied factor or table of summary statistics should contain only two groups or two variables.

Value

The returned frame contains the following components:

Diff

the difference between the two means

SE

the standard error of the difference

df

the degrees of the freedom for the difference

LL

the lower limit of the confidence interval for the difference

UL

the upper limit of the confidence interval for the difference